Well, if she can cum from anal, I'd guess you're halfway there.
Add a man into the mix, and make her service him.
If he's happy, she can get some relief from being a girl...
Otherwise, she stays in chastity indefinitely.
Combined with some effort, maybe some hy pn os is, you should be able to twine his orgasm with her orgasm... Keep her horny and edging and tease her for hours before your man comes in, and make sure she learns to cum from giving head or being used... When he spurts, she can (or is f_o_r_c_e_d to)... If it's not immediately at that moment, she gets nothing.
Make sense?
You'll want to make it a treat for her though... It's a REWARD, not an obligation. If she's a good gurl, she gets to make him cum, and she MIGHT, if it's intense enough, cum as well.
OTOH, she could perhaps be allowed to cum like a gurl without his seed spraying her, but... I think making it more mental would be beneficial. She knows he came, she orgasms. She thinks he came, she orgasms...
