Consent in Sexual Offences
The element of consent "is generally the most important issue with regard to sexual assault".
Consent applies to both the actus reus and mens rea of the offence. The actus reus concerns whether "the complainant was subjectively consenting in her mind" and the mens rea concerns whether "accused believed that the complainant communicated consent".
The absence of consent must be determined on a subjective basis of the complainant "by reference to the complainant's subjective internal state of mind towards the touching, at the time it occurred."
There is no obligation that the complainant "express her lack of consent or her revocation of consent" before the actus reus can be made out.
If the trial judge believes the complainant subjectively did not consent, the Crown has proved the absence of consent. The accused’s view of the complainant’s conduct is not relevant to whether the actus reus has been established. 
There must be actual consent. It is not a defence to sexual assault to suggest implied consent.
Consent must coincide with the sexual activity and can be withdrawn at any time.
The proof of lack of consent requires that the accused "knew that the complainant was not consenting to the sexual act in question, or was reckless or wilfully blind to the absence of consent.".
In certain cases, the accused may raise a defence of honest but mistaken belief in consent. In relation to offences of sexual assault, sexual assault causing bodily harm (or with a weapon), or aggravated assault, consensual sexual activity must be consensual within the meaning of s. 273.1(1) of the Code. Section 273.1 states:
Meaning of “consent”
273.1 (1) Subject to subsection (2) and subsection 265(3), “consent” means, for the purposes of sections 271, 272 and 273, the voluntary agreement of the complainant to engage in the sexual activity in question.
Where no consent obtained
(2) No consent is obtained, for the purposes of sections 271, 272 and 273, where
- (a) the agreement is expressed by the words or conduct of a person other than the complainant;
- (b) the complainant is incapable of consenting to the activity;
- (c) the accused induces the complainant to engage in the activity by abusing a position of trust, power or authority;
- (d) the complainant expresses, by words or conduct, a lack of agreement to engage in the activity; or
- (e) the complainant, having consented to engage in sexual activity, expresses, by words or conduct, a lack of agreement to continue to engage in the activity.
Subsection (2) not limiting
(3) Nothing in subsection (2) shall be construed as limiting the circumstances in which no consent is obtained.
1992, c. 38, s. 1.
Where belief in consent not a defence
273.2 It is not a defence to a charge under section 271, 272 or 273 that the accused believed that the complainant consented to the activity that forms the subject-matter of the charge, where
- (a) the accused’s belief arose from the accused’s
- (i) self-induced intoxication, or
- (ii) recklessness or wilful blindness; or
- (b) the accused did not take reasonable steps, in the circumstances known to the accused at the time, to ascertain that the complainant was consenting.
1992, c. 38, s. 1.
Analysis of consent for sexual offences requires a two step process:
- determine whether there is evidence establishing there was no "voluntary agreement of the complainant to engage in the sexual activity in question" (s. 273.1(1))
- if there was consent (or a reasonable doubt of a lack of consent), then "consider whether there are any circumstances that may vitiate her apparent consent".
The first step "requires proof that the complainant did not voluntarily agree to the touching, its sexual nature, or the identity of the partner." Other conditions or qualities of the act, such as whether effective birth control was being used or the existence of a sexually transmitted disease are not relevant at this stage.  The "sexual activity in question" refers to the specific physical act, whether it be kissing, petting, oral sex, intercourse, or the use of sex toys. This will be as precise as the form of penetration or the part of the body to be touched. The sexual nature of the offence should distinguish from other forms of non-sexual activity such as medical examinations. The identity of the sexual partner refers to "a specific individual known personally to her". Where the complainant is mistaken then there can be no consent on this first stage.
In this first step the Crown must prove the absence of a subjective voluntary agreement to the sexual act in question. The absence of consent, as an element of the offence, is "judged subjectively from the complainant's point of view".
Section 273.1(2)(c) does not require coercion. It is applicable where the “use of personal feelings and confidence engendered by that relations to secure an apparent consent to sexual activity”.
- R v James, 2011 BCSC 612 (CanLII) at para 18
R v Ewanchuk, 1999 CanLII 711 (SCC),  1 SCR 330 at para 27
R v Nguyen, 2017 SKCA 30 (CanLII), at para 8
Nguyen, ibid. at para 8
R v Dippel, 2011 ABCA 129 (CanLII) at para 13
R v JA, 2011 SCC 28 (CanLII) at para 37
Ewanchuk, supra at paras 48 to 49
Ewanchuk, ibid. at para 26
J.A., supra at para 37
- Ewanchuk, supra, at para 29
- Ewanchuk, supra, at para 31
- R v Hutchinson, 2014 SCC 19 (CanLII) at para 17
J.A., supra, at para 24
J.A., supra at para 24
- R v Hutchinson 2014 SCC 19 (CanLII)
- Hutchison, ibid. at paras 5, 55
- Hutchinson, ibid. at para 54
Hutchinson, ibid. at para 57, 58
Hutchinson, ibid. at para 58, 63
- Hutchinson, ibid. at para 55
- Hutchison, ibid. at para 17
- R v Lutoslawski, 2010 ONCA 207 (CanLII)
Sexual Activity in Question
Consent in sexual assault set out in s. 273.1 requires "voluntary agreement" between the persons to "the sexual activity in question". This is meaning is restricted to the complainant's subjective agreement to the "touching and its sexual nature".  The "sexual activity in question" refers to the "physical sex act itself (for example, kissing, petting, oral sex, intercourse, or the use of sex toys)."
- R v Hutchison, 2014 SCC 19 (CanLII)
- Hutchison, ibid. at para 54
Statutory Exceptions To Consent
Section 265(3) deems an absence of consent despite evidence of consent in certain circumstances consisting of:
- application of force to complainant or another (s. 265(3)(a))
- threats or fear of force to the complainant or another (s. 265(3)(b))
- fraud (s. 265(3)(c))
- exercise of authority (s. 265(3)(d))
The circumstances set own section 265 (3) identify "situations in which it complainant's apparent consent is not effective because it is not a true reflection of the exercise of the complainant's free will".
The term "exercise of authority" under section 265(3)(d) is intended to capture relationships in which one party has "the power to influence the conduct and actions" of others.  however, influence "is a question of degree" whereby at some point "influence becomes coercion and a parent consent is nothing more than submission". it is when it becomes coercion that section 265(3)(d) is engaged. 
and accused is in a position of authority when he "can course the complainant into consent by virtue of their relationship".  Such positions can include doctor-patient relationships or student-teacher relationships.
The burdens upon the ground prove beyond reasonable doubt that the parent consent was obtained by the exercise of "coercive of authority". 
"Consent" in s. 273.1 refers to "consent as the conscious agreement of the complainant to engage in every sexual act in a particular encounter." Consent requires "a conscious, operating mind, capable of granting, revoking or withholding consent to each and every sexual act." 
All non-verbal behaviours that are being relied upon as "expressions of consent" must be "unequivocal".
A sexual encounter between two strangers requires "as a matter of logic and common sense ... clear and unambiguous communication of consent". Depending on the circumstances, context of the prior relationship "may, in certain circumstances, impliedly provide scope for the perception of the existence of consent".
- R v Hutchison,  1 SCR 346, 2014 SCC 19 (CanLII), at para 4
- R v Geddes, 2015 ONCA 292 (CanLII) at para 32
- R v J.A., 2011 SCC 28 (CanLII),  2 SCR 440, at para 29
- JA, ibid. at para 29
- R v Matheson, 1999 CanLII 3719 (ON CA)
- Geddes, supra at para 34
- Geddes, supra at para 36
- Geddes, supra at para 37
- Geddes, supra at para 36
- JA, supra at para 31
- JA, supra at para 44, 66
R. v. S. (T.),  O.J. No. 268 (QL) (Ont. Ct. J. (Gen. Div.), Hill J. stated at para. 158
S(T), ibid. at para 158
S(T), ibid. at para 158
Capacity to Consent
Section 273.1(2)(b) deems there to be no consent where "the complainant is incapable of consenting to the activity".
Burden of Proof
The Crown has to prove beyond a reasonable doubt either the absence of a capacity to consent or the absence of consent as a fact.
Standard of Proof
Incapacity is established where the evidence is shown that the complainant is "incapable of understanding the sexual nature of the act" or was "not able to appreciate that they may choose to decline to decline to participate in the activity".
Effect of Incapacity
If incapacity is established, the Crown does not need to prove the absence of any prior consent.
Lack of Memory of the Event
The alleged victim's loss of memory of the event "is direct evidence of nothing except the fact that the witness cannot testify as to what happened during a particular period". It can also permit, in combination with other evidence, the inference that alleged victim did not or was not capable of consenting. While not strictly necessary, "expert evidence will almost always be essential" is such a case.
R v Haraldson, 2012 ABCA 147 (CanLII) at para 17
R. v. Jensen (1996), 1996 CanLII 1237 (ON CA), 90 O.A.C. 183, 106 C.C.C. (3d) 430 at 439
Jensen, supra appeal to SCC quashed, 1997 CanLII 368 (SCC),  1 SCR 304
R v Ashlee, 2006 ABCA 244 (CanLII) at para 20
R v R. (J.) (2006), 2006 CanLII 22658 (ON SC), 40 C.R. (6th) 97,  O.J. No. 2698 (QL) (Ont. S.C.J.), per Ducharme J.
R v Cedeno,  O.J. No. 1174 (C.J.)<
- R(J), ibid.
- R(J), ibid.
An unconscious person cannot provide consent in advance. Such a person is "incapable of consciously evaluating whether she is consenting is therefore not consensual". Consent requires an ongoing conscious consent throughout the sexual activity.
As for capacity to consent, courts can infer a lack of capacity where there is direct evidence that:
- the complainant was extremely intoxicated;
- the complainant was asleep or unconscious when the sexual touching commenced; or
- the complainant was asleep or unconscious during all of the sexual touching (B.S.B., supra at para 45).
The capacity to consent requires more than simply the “baseline physical functions”.
It is not so low as to render "relatively primitive actions such as walking a short distance, or unassisted vomiting" as being signs of capacity to consent.
Drunkeness is not the same as incapacity. Poor decision making, memory loss, or loss of inhibition or self-control due to alcohol does not negate consent. An intoxicated complainant may still have the ability to consent.
Where alcohol may have vitiated consent, it may be best established by way of expert evidence. But it is not necessary as a matter of law.
Consent may be vitiated by abusing a position of trust, power or authority. 
Threats or abuse that occur after the event cannot go towards vitiation of consent.
The judge may not make a finding that consent was "not possible" on the sole basis that the complainant was "drinking heavily".
- Haraldson, ibid. at para 7
R v JWM,  O.J. No. 1295 (S.C.), per Hill J
- R v Jensen 1996 CanLII 1237 (ON CA), (1996), 106 CCC (3d) 430 (Ont. C.A.)
- R v Merritt,  O.J. No. 1295 (Ont. S.C.J.) (*no CanLII links)
- R v R.(J) 2006 CanLII 22658 (ON SC), (2006), 40 C.R. (6th) 97 (Ont. S.C.J.) at paras 17‑19, 43
R v Faulkner 1997 CanLII 1193 (ON CA), (1997), 120 CCC (3d) 377 (Ont. C.A.))
R v Merritt
R v Hernandez, 1997 ABCA 297 (CanLII),  A.J. No. 955 (Alta. C.A.)
R v Cedeno, 2005 ONCJ 91 (CanLII), 195 CCC (3d) 468 at para 18
- R v Asfour, 2006 CanLII 577 (ON CA)
- Asfour, ibid.
- R v AW, 2008 NLCA 52 (CanLII)
In a sexual assault context, fraud will vitiate consent where an "objectively dishonest act" (i.e. falsehoods or failure to disclose) has "the effect of exposing the person consenting to a significant risk of serious bodily harm". To be dishonest, the acts must be those that "a reasonable person would find them to be dishonest".
The failure of the accused to disclose that they are HIV positive before sex can vitiate any consent for sex that the victim gave.
Where "deception causes a misunderstanding as to the nature of the act itself there is no legally recognized consent because what happened is not that for which consent was given"Consent that is not based on a knowledge of the significant relevant factors in not valid.