Am I crazy?

Husband and I had rocky past many years ago. I got a weird feeling and looked at his messages on his phone, on Instagram he messages a girl we both went to school with that he is/has been friends with. I see she offered diapers recently and he picked them up on the way home never mentioning it to me and when I saw them today I asked where he got them and he said a coworker not the girl who he actually got them from. I can’t tell him I know he didn’t since he would know I went through his phone. But does that seem weird that he would lie about where he got them?