Sexual assault is NEVER the girl’s fault. (When it happens to a female, likewise with a guy but I’ve seen many boys victim blaming)
It is NEVER EVER the victim’s fault. Putting an arm around someone you care about doesn’t mean you have consented to a finger down your pants.
Doesn’t matter what gender the person is! It’s a friend gesture and guys getting “confused” is their fault.
Stop using your penis as an excuse to touch girls in inappropriate ways. Grow the fuck up!