If you're gonna tell someone to pull out, but then you lose yourself in the moment and use all your leg strength, two of the strongest muscle sets on the human body, to lock him in and he cums inside you as a result, you don't have a right to demand he pays for your Plan B. If he offers to pay for it, then cool. If not? It stopped being his responsibility after you went back on your own demand that he not cum inside you.
I, too, enjoy the occasional dose of karmic retribution. They both really got what they deserved. The only difference was that one of them worked their ass off to make it while the other one simply floundered in her lot.