Thanks ladies. I talked to him about all of it and how it looks when put all together.
He acknowledged that it does look bad, and apologized for making me uncomfortable. He still doesn't understand why it bothers me , he says that she is in no way a threat, that they haven't even messed around physically in over 2.5 years. He admitted that they did some things over the phone near the beginning of the relationship, before things were official between us.
We don't have a 100% conventional/traditional relationship, so some things don't bother me and some do- we have different standards of okay/not okay than most, I think. I just wanted to make sure that I wasn't being all emotional and whatnot.