It probably happens to me .9 out of 1.0 times I do it.. It feels like stabbing my gf, even though I ask her if she wants it harder and deeper... she say yes... I try to go slowly but sometimes shit happens. Not a big deal after all ... I think the only condom I have broken was doing this... before I notice the condom was broken I caused lots of pain with a single thrus so maybe it broke when I hit something at the end, a muscle a bone who knows.