Leverage her power.

You don't bother answering, instead slithering your vines up around her thighs, pulling them open with ease. Oh you poor thing...haven't recovered your strength from my trap yet have you? Here, let me heal you... You slide a vine through the cleft of her ass, sliding between her legs to gently rub across her shaved lips. "Wait! STOP!" She bucks and curses in protest, "You can't! I have to keep my virginity to channel my goddesses power! STOP PLEASE!" To her surprise, you do.

Hm. So you're asking me not to violate you because it would take away YOUR power? Not because it would distance you from your goddess or some religious blibberblabber? Her eyes widen and her mouth opens but no sound comes out. Y'know, if I were a goddess, I'd be pretty angry that my follower was only following me because they wanted my power. Her face turns slightly green and her eyes flick skywards. But I'm sure you can ask forgiveness later if I don't take your virginity... She looks back at you hopefully. ...but you'd need to offer me something pretty fantastic in exchange for a favor like that.

Her face falls and she swallows nervously. You continue lazily stroking her pussy lips, delighting in her squirming. Tick tock Dana...what's it gonna be? At the same time, you pump your vine up and down between her ass-cheeks, hotdogging her delicious rump.