Okay, so this sounds literally exactly like a movie plot, but in real life it’s just a really bad idea. Money is super nice and buying cool stuff is great, but it’s not worth throwing away a real relationship for. If you leave your boyfriend for his rich friend, you’re just gonna look like a gold digger and everyone will talk about you.
Plus, think about how awkward it would be if things went wrong. You’d lose your boyfriend AND you’d make things super weird in their friend group, and honestly the rich guy is probably just using you anyway. Guys like that think they can buy whatever they want, and you don’t want to be treated like an object that he just purchased with his allowance.
You gotta decide if you actually love your boyfriend or if you just want a sugar daddy. If you love your boyfriend, ignore the rich friend completely and tell him to back off. If you really want the rich guy that bad, break up with your boyfriend first, because cheating is so trashy and you’ll just end up with nobody respecting you.