Boyfriend still talking to his ex?

So my boyfriend and I have only been together for about two weeks now. We were talking for almost two months before he asked me to be his girlfriend so us being a “thing” isn’t new. Him and his ex broke up like 2 weeks before we started talking and they still have and keep a streak on Snapchat and the other day while him and I were together they were playing 8 ball pool on iMessage games. I know this all seems very juvenile, but it’s not the fact that it’s streaks or games it’s just the fact that every time we hang out I just so happen to see her name pop up on his phone on Snapchat or iMessage bc of their streak and games. Idk what to do, I did tell him that it makes me uncomfortable but I won’t and wouldn’t ever ask him to drop his friends for me especially because they were there first. I just don’t know how to be okay with it.