Hurt :-///

So I couldn't sleep last night....at first I was just watching tv and playing games on my phone but I got bored and then I noticed my husband had left his phone downstairs.....you know I was nosy. In his email were multiple messages in response to posts in the "causal encounters" section on Craigslist. There was back and forth on some of them, nothing intimate or explicit but he did send a pic(just his face) to one and give out his phone number. I woke him up and confronted him. He says he was just bored and wanted to talk to people. As stupid as it sounds he actually is kinda like that, just randomly social. I just don't see why he went there....I want to believe him but I'm just really having a hard time. Needed to vent and wouldn't mind opinions.