Is my husband sneaking around? Or was…

My husband of almost 2 years said I could go on his IPad and watch some tv shows. He has like Netflix and all other streaming services. I went to his subscriptions and saw this. It looked like he had a free trial or something and it’s a dating app! About 3 weeks ago we had sex and he had a pillow behind my head and I thought something was off and then when I climbed on top of him and saw that he tried hiding his phone… he was on Reddit! I saw naked girls on there and confronted him about it. He said he was looking at sex positions that we could do together… but didn’t make since he tried to hide it from me and we was already having sex? I told him if he wanted to do different positions then why look at that while we are already having sex? It doesn’t make sense to me. Then I started freaking out because I couldn’t tell if he was lying or not. When we had sex before he never used to do that ever. But all a sudden now? Am I just tripping or what?