Need help

Today I came home and saw what looks to be a girls makeup on a wet wipe in the garbage can. Well my BF has cheated on me before so I quickly jumped to conclusion and asked if a girl was here. He said no, our son had ice cream and he wiped it off. I then believed him and he called his mom at midnight to prove it. I just feel he took it a bit far by calling his mom. I can't help I feel the way I do. How would you feel in this situation?