Hopefully, he has someone he trusts enough to confide in. Counseling can help, too.
Humping is a behavior more commonly associated with sexual arousal or dominance rather than with sexual orientation. It may be a form of play or a way to establish social hierarchy. If it is happening in a sexual context, it may be related to curiosity, experimentation, or other reasons specific to the individuals involved.
He is straight.
Soko's sexual orientation is heterosexual/straight.
Straight
He is. Straight
He is straight.
Straight
No he is not, he is 100% straight.
He's straight.
If you are "straight", it means you prefer the opposite sex - as opposed to gay.
He's straight
He was straight.