Boyfriend talking to girls as friends

This might be a long one so buckle up. My boyfriend and I have been together for about 3 years now. He had cheated on me during the first year by sending dick pics to a girl and it has left me traumatized. But I’ve been aptly working through it. Recently he has been talk to one of his musician female friends everyday as well as liking her pics on social media. They were even sending voice memos back and forth at one point. I truly believe they are friends from HER point of view because I know this isn’t the only person she talks to on a regular basis. BUT I can’t help but feel that maybe he is attracted to this person and possibly trying to flirt subtly. He has expressed that they are purely only talking about creativity and their music, but it’s hard for me to wrap my head around.

Do your boyfriends have close girl friends? If so, how do you feel about it?