I can tell he’s lying but..

Okay, sooo, I need help here. A few months ago, I was joking around with my boyfriend about his work. He met his last girlfriend at his old job. And while talking about his work now, he mentioned how his manager is a year younger than him. And continued to say that he wishes he could get to that point too. I find out it’s a woman and I jokingly say, “is she cute?” And he actually told me that yes, she was attractive but he loves me and it’s his manager. I’ve never had a BF so honest but I thought it was cool he didn’t diss her to make me feel better so whatever.

So, yesterday I was trying to share a photo from his phone to send to myself. Once I clicked share, a list of people came up and there she was, the first person. I asked people on here what that means and I guess it means it’s the most recent person he might’ve talked to. Honestly, I kinda freaked out because all I see are cheating stories on here and I thought he was hiding something.

Well, he got so mad at me for accusing him of talking to her. He said he only talked to her once but it was to ask about his schedule. He said things like, “she’s a cool person and a good manager, but you’re my girlfriend. I don’t like her like that, she has a boyfriend too, we weren’t talking like that”. That’s when I said, it doesn’t matter if someone has a girlfriend or boyfriend, it doesn’t stop everyone (I’ve read too much Glow lol). So I asked him to see their messages and of course, they’re gone. Deleted. I asked why he’d delete it if he was just asking about work. He tells me he clears out his messages frequently if they’re useless texts. Guys, it’s really hard for me to believe this and idk why he got so angry, he sounds guilty of something but he doesn’t sound guilty of cheating. I don’t get those gut feelings towards him. I always get them and I’m always right, and this time, it just didn’t happen. So I feel like he’s lying about something but he wasn’t actually doing something wrong. IDK if he was just worried I’d see it and assume something and get mad or what. He’s been single for three years and his last ex was very controlling and emotionally abusive, idk if this is just a natural response of his because he’s sensitive to it. Help!

Would you stay mad over something like this if your gut feeling was telling you that it’s fine?