Newish BF. We do spend a lot of time together and he has a lot of friends and interests who are important to him, which is good.
So, when we're together he is often replying to or sending messages. Some will be a checkin on someone he either speaks to regularly or hasn't heard from for a while, some will be banter in a group chat, some will be plans and arrangements for something he's going to or something he's trying to gather a group together to go to.
I love all this about him, he 's proactive in friendships and in making thins happen/finding things to do, but I do find it rude when e.g. we're sat in a restaurant and he's on his phone. He'd say he's with me so.much that if he didn't do it when he's with me he'd never do it, which does have an event of truth.