ABYG for requesting boundaries between my SO and his female friend?

I (F) messaged my SO's(M) close female friend the other day asking why their friendship doesn't seem to have some boundaries and told her I'm uncomfy with it kasi ofc he's already in a relationship ++ I asked her abt smthing that she said in their convo regarding abt us as well.

for context: girlie is inviting my SO on a pool party for her female friend's bday, that specific female friend celebrating the bday confessed to my SO a few years back that she liked him even though we're already together at that time, I felt disrespected kasi I thought that was just so unnecessary and weird. Like why would you still confess to someone who's already in a relationship? It's like she's just trying to stir things up. So, given that history, when my SO told me abt it and said na if I'd allow him to go then he'll go, I said I'm uncomfortable with him going there since that Girl will be there + silang tatlo lang magkakakilala dun ++ it's also the day of our monthsarry. I told him I'd be uncomfortable but if he'd still go edi so be it.

He refused to go and showed me a screenshot of him declining to come dun sa gc for the swimming. Few days later, on the day of our monthsarry, SO's female friend messaged him again convincing him to go, he told me abt it then I said, I already answered him last time that I feel uncomfortable and that didn't change. He then told his friend na he can't go kasi "tali" na raw sya. He sent me the convo again and that's where I felt off sa mga nabasa ko. So I asked him if he could show me the full convo kasi this female friend keeps making pilit him to come. He showed it to me a few days later and wow, my SO kept saying na "tali na sya" "nakawin mo ko rito" nung inaaya sya for the swim, the female friend then had some icky responses like "sana makawala ka na".

He mistakenly showed me their ig convo as well and I saw that they often talk there as well, with my SO even always replying to the girl's ig stories. On messenger they talk almost everyday as well, there were even some updates or random chats like nung napag saraduhan ng gate bf ko and he randomly messaged the girl na pagbuksan sya ng pinto even though they don't live together, like what was that even for? I even saw na he's always sharing random vids or reels to her and I realized that it's the same things na shineshare nya sa convo namin.

It was so uncomfortable, I confronted him abt it and we had a fight. I asked if I can talk to the girl since that's his friend and he said I can so I messaged her after I calmed myself down. SO and I are okay now and we already reconciled, he apologized and blocked the girl, I told him he shouldn't have done that and that doesn't solve the problem.

Girl's response to me after I messaged her was just so off and I felt dismissed like she refused to acknowledge her part on this problem.

I can paste here some bits of the convo if some of u would need to see it for some more context. I apologize if this got too long na ata.