I do think Demokan brings up a very valid subject clearly linked to Dawkin's experience. But it is a very slippery one when it comes to the "age of consent" and legal issues that vary from country to country, and culture and highly charged with emotion.
Reading Demokan's posts I was reminded of one of Pedro Almodovar's films. He made his film, "What Have I Done to Deserve This?"in 1984, and I think that the Spanish Age of Consent at the time was 13.
The film was in the genre of Spanish black comedy. It told the story of a struggling housewife with an abusive husband and dysfunctional children. The youngest (aged 11 or 12) is having an affair with his (male) dentist, and when his mother says something about, he responds in almost the same words as Demokan. (i.e. Its my body, I'll do what I want with it.).
Demokan's posts indicate that he may not have thought out all the issues.
Assuming he is underage and takes the initiative to have sex with an older person of either sex, he is potentially involving the older person in a crime that could have serious consequences for the older person and even for himself.
I said potentially, because Canadian Law (as defined by an entry in Wikipedia, which may not be the best source) has some exemptive clauses.
The Tackling Violent Crime Act took effect on 1 May 2008, raising the age of consent from 14 to 16. 
There exist two close-in-age exemptions, depending on the age of the younger partner. A youth of twelve or thirteen can consent to sexual activity with an individual less than two years older than they. A fourteen- or fifteen-year-old can consent to sexual activity with a partner who is less than five years older than they. 
Criminal law (including the definition of the age of consent) is in the exclusive jurisdiction of the federal government, so the age of consent is uniform throughout Canada. Section 151 of the Criminal Code of Canada makes it a crime to touch, for a sexual purpose, any person under the age of 16 years. Section 153 then goes on to prohibit the sexual touching of a person under 18 by a person in three circumstances: if he or she is in a "position of trust or authority" towards the youth, if the youth is in a "relationship of dependency" with him or her, or if the relationship is "exploitative". The term "position of trust or authority" is not defined in the Code but the courts have ruled that parents, teachers, and medical professionals hold a position of trust or authority towards youth they care for or teach. For determining whether or not a relationship is "exploitative", s. 153 (1.2) of the Code provides that a judge can consider how old the youth is, the difference in ages between the partners, how the relationship evolved, and the degree of control or influence that the older partner has over the youth.
The "position of trust under 18" anti-exploitation rules were expanded in 2005 by Bill C-2 where a judge may choose to term a situation to be sexual exploitation based on the age of the younger party, age difference, evolution of the relationship (how it developed, e.g. quickly and secretly over the Internet), the control or influence over the young person (degree of control or influence the other person had over the young person). This passed before the 2008 amendments, and they were not repealed so they are still in effect and can apply towards adults in these situations with young persons over the age of consent and under 18 (16-17).
Where an accused is charged with an offence under s. 151 (Sexual Interference), s. 152 (Invitation to sexual touching), s. 153(1) (Sexual exploitation), s. 160(3) (Bestiality in presence of or by child), or s. 173(2) (Indecent acts), or is charged with an offence under s. 271 (Sexual assault), s. 272 (Sexual assault with a weapon, threats to a third party, or causing bodily harm), or s. 273 (Aggravated sexual assault) in respect of a complainant under the age of fourteen years, it is not a defense that the complainant consented to the activity that forms the subject-matter of the charge.
Hence a 15 y.o. (if the wikipedia entry is correct) could have sex with a 20 y.o and the older partner would not be committing a crime.
It is also clear that Demokan is in an extremely angry phase of his life. I can understand his frustrations, particularly in connection with being forced to participate in JW activities.
But anger is a poor motivational force when it comes to sex. Sex is a very powerful (and wonderful) force in our lives, and its easy for it to get out of control, which can lead to some unpleasant consequences. I hope this young guy only acts with a lot more forethought.