My sister-in-law and I are aware of each other. While our parents were away on a trip, we finally kissed... but she refused to have sex, saying 'Once you start having sex, you can't stop.' But I couldn't hold back either, so what was supposed to be just rubbing turned into an uncontrollable urge to insert! My sister-in-law felt the same way, and as we rubbed against each other, we pretended it was an 'accident' and inserted. We couldn't stop with the intense thrusting and ended up having intercourse with internal ejaculation. Until our parents came back, we had internal ejaculation sex dozens of times.
