AIO- text my bf sent someone

I normally do not go through my boyfriend's phone, but him and I have our gmails linked. Earlier today I got an email notification that said he had an unopened message from someone with a suggestive username. These texts were from last month but we have been together since November 2023. He also tells me he doesn't want me to pierce my face, like the girl in chat has done. Also, when I first confronted him about it he didn't say anything so l went to the bedroom. I texted him (as shown) and he left me on read. I personally wouldn't consider this cheating but it makes me feel really weird. Definitely something that I think I need to talk to him about. AlO???