Boyfriend messaged girl streamer

Hi girlies feeling a bit confused. My boyfriend is into egirls that’s his type basically. His had a habit of constantly looking at them and had his socials full with them. After talking about how it makes me feel unfortable he said he’d stop. But recently I found out he’s been watch an “egirl” streamer he says for like only 30 mins when he gets home from work and has added her on discord to message her when she’s streaming next. He’s never mentioned liking her streams or wanted to share her with me which I find off if you watch them regularly and enough to seek out and message them for more. I know he’s not told me because he knows it would make me sad. This is an insecurity I’m working on and understand it’s not good but I can’t help how I feel now. I confronted him and he said he’s sorry and it was harmless. Any advice please

Edit

Found out he’s been spending money on her stream to like gift subs and stuff :(