How should I handle this girl cheating on her boyfriend?

Alright so in general let’s say a girl has been dating a guy for a year and they’re planning on getting a house in 6 months. That girl has crossed several boundaries with me over the course of that year (telling me to come over and “make her shut up”, telling me she’s good at sucking dick, checking my location on snap, asking me to pick her up to get food while she’s drunk). The boyfriend is a very nice dude and has been described as a golden retriever type. He’s also seemed a little suspicious of her behavior. I’m top of this, multiple people have said they seem like friends more than boyfriend and girlfriend. I finally called this girl out on her shit and she blocked me and got me fired from the job all three of us work at about three weeks ago (she claimed I was harassing her). I am now planning on telling her boyfriend everything.

Is this a good idea and is it likely he’ll even respond or believe me?

How should I handle this girl cheating on her boyfriend?
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