I think this is the hardest part of any of these situations: does the other person already have someone else.
If you cannot find evidence I would say either assume there is someone or assume that there is no one. There are too many ways that arrangements can be made (new credit card, paying in cash, having the other person pay, and OwnIt mentioned other things). If those things happen there is NO WAY you can detect it.
But I definitely get it. I too am thinking what she is telling other people etc. It drives you insane and doesn't help.
Would it be easier for you to assume there is someone else and that IF he wants to recommit to you HE will have to do the hard work of convincing you there is no one else.
OR to assume that he needs space/time and IF he comes back you assume there was no one else. OR if there was someone else that he made the choice that you are more important.
