If I let you fuck me now... I don't think you'd even get it all the way in before you popped. And considering what we are working with, "all the way in" isn't really that much...
You are failing this stamina test, baby... but a deal is a deal, you can still fuck me soon, on your birthday.
Get to the edge again, hold back baby, don't cum, and not so fast this time. Only a medium pace.