My current boyfriend and I haven't been together all that long, but he spent the night a few days ago and we decided to have a little fun. He had some trouble getting it in, which I've never had happen before, and after two thrusts inside, he was finished. We did this three times, and every time was the same. I've never had this happen and I'm feeling like I did something wrong. We talked about it and he said he lasted 5 minutes with his last girlfriend. Any advice?