[quote=WizardGirl]
Just gonna put the facts here:
Ashley and him knew each other many years ago
He is older then her
She isn't as effected by his 
It would be wrong in the USA if they had sex
[/quote]

All notions of age are thrown out of the window to Weiss since he's not going to keep up with who is what age. And he can't really care about laws, even if he cared he'd just hop over to a place where whatever he has in mind is perfectly acceptable.

Oh and btw, Weiss is immune to mind-affecting effects remember? He is slightly attracted because well.. he is a devil: he's attracted to a lot. This is going to be fun. Right after a conversation with Saren.