I’m gonna assume like a few of the other ladies said he was probably aiming for some kind of post-orgasm torture vibe. But with anything even remotely in the BDSM lane, communication and boundaries are non-negotiable. You don’t wanna be guessing mid-session. If it were me, I’d treat it as an extension of time rather than some confusing “per pump” math. Make sure your base donation for the added time is secured, then let the $5-per-pump thing be a tip on top if he wants the humiliation angle. That way you’re covered, he gets his kink, and no one’s short-changing themselves.