How to cum?

Kristelle

So my FWB wants to make me cum from oral. I have only cum once from oral and that was many many moons ago. When I masturbate I can only cum when my legs are straight/knees locked. I used to be able to do it with bended knees, but now I can’t. I need tips or advice? I feel like because I can only make myself cum when my legs are straight, that affects how I can cum when receiving oral.

TIA ❤️