"Giving up a few orgasms doesn't seem like too much for what we do here, does it? It may not mean much to you now, but my research could change the world in ways you are a long way from realizing.
But let me blunt. What surely matters more to you is that in exchange for this sacrifice you will get to see more tits and ass than you ever dreamed. And if you stick with it, even some pussy. What do you say?"
"Okay." you reply.
"Okay I will help with your study."
"And?" she insists.
"And I promise to only cum on Fridays!" you finally blurt out.