Who is the likely father?

My ex is pregnant. We are still friends and not exclusive, but have kept having . However, she had ual encounters with a male friend of hers. Here is what happened with them. They did not have , but he did on her rear end and some of his semen did travel down to her l area, but it didn't get inside, unless maybe while she was cleaning it off with tissue somehow. This happened twice within a week. There was a time of two or so weeks that we did not see each other or have , which is when this happened between them. Just prior to this break of ours we had unprotected , and I pulled out a little late, leaving a small amount of semen in her. Her cycles are irregular and pinpointing her ovulation is a difficult task. I just need some educated guesses as to who the likely father is. I know either way is theoretically possible, but what are the odds that it is me who is the father?