Do you think my bf is cheating?

I was hanging at my bf’s house watching tv, while he was in the shower. All of a sudden I’m on my phone phone, when I get a text from him saying “Call me when you’re free”. So, when he came out the bathroom I said to him “you just texted me” he said what did I say?” then I told him, and he said “oh yeah that was from earlier” 🙄 I was going to sneak and look in his phone, but I’ve never done that before. Idk what to do.