friend issue

so I have this friend who I got really close with and I got close with her family, I'm not attracted to her (I'm bi/ace). recently, and by recently I mean it's been a month, she got her first girlfriend and ever since theyve CONSTANTLY been at it, with their tongues down their throats grabbing each other. they had sex at a sleepover I was at and they k n e w I was awake when they did it. they are absolutely disgusting with each other I cant carry a conversation with either of them anymore. me and all of my other friends have started cutting them out because of how bad it is. I feel bad for doing it bc I hate cutting people out and losing friends but I cant handle it anymore, and if I talk to them about it theyll call me homophobic because that's what theyve been calling everyone who has complained to our directors about them (because they make out and shove hands down pants in the band room and crawl across the stands to get to each other at games) I dont know what to do please send help