The Sexual and Reproductive Health Resources for Adolescents and Young Adults are online resources aimed specifically at adolescents and young adults.
Most likely these boys are heterosexual, but the culture is set up so that they have no problem sucking down another man's semen.
In fact, this semen supposedly holds a sort of "life-force" that is only to be kept amongst other men. 1: Hey Flies with Eagles, are you thinking about taking down Chief Crouching Bear's cum pretty soon?
In these tribes, women only get to receive the sweet, illusive semen if the couple is attempting to procreate. 2: Fuck yeah, after all, that's the only way to becoming a man...
3: But you like women, so doesn't that make you bi-curious?
You don't have to date a guy for six months to get the lowdown on who he really is.