My grieving partner situation

Well my bf recently lost his mother. While I did my very best being there for him. He was seeking i don’t know what to call it maybe emotional support/comfort from other women. One is his ex. I saw he was having conversations with women not sexual but I know these aren’t people he would normally reach out to. Some don’t even know he was grieving. My woman’s intuition told me to check his phone when I noticed he feels distant. That’s when I found out he’s been in people’s DMs

When I confronted him he gets pissed, he’s like I’m not cheating on you these are just texts and stop threatening to end the relationship if you wanna go just let me know I’m not in the mental state to be getting into it with you right now. We previously also had a problem with the said ex by the way he told me he would delete her, now I know he just changed her name in his phone.

While I understand this is a sensitive time for him should I withhold my emotions just because he’s grieving? I’m not a person who keeps quiet about things bothering me but now I don’t even feel the need to talk about it anymore. I feel like packing up and leaving but I’m also feeling guilty. He was there for me when I lost a very close family member too and I feel like it’s only fair that I give him support. Three days now we’re not talking he tried talking to me to basically say let me know what you decide to do. And yesterday he got too drunk puking everywhere, obviously I helped him not that he asked me to.

I’m just lost mentally emotionally and I could use some advice. Thanks ❤️