for me it only has been recently. We were on the floor and I was on top. We were going like mad when I pulled all the way out and went to go back and 'bent my wookie.' That reallly hurt.
The other one was on her roomates bed (
) I was on top with her legs on my shoulders. We were all lubed up and I pulled all the way out and shifted her slightly on my shoulders. Well that changed the angle of entry and when I went to go back in (hard) I thrusted twice before noticing how different it was. Well I pulled the classic 'oops' move and she ended up bleeding. I still feel really bad because I knew it could happen and I wasn't more careful about it. (Sorry SL!)