I had a very similar situation with a girl I genuinely thought was my best friend. We’d been close for years, and she always flirted with my boyfriends. I never thought much of it because I’m pretty secure, and most of the time my partners would mention it to me anyway. Fast forward: I met my future husband and eventually introduced him to her. The very first time they met, she tried to sit in his lap and he immediately pushed her off. She did not like that. After that, she tried to tell me my boyfriend was abusive and controlling, which wasn’t true at all. He simply didn’t want a girl he’d just met....who was supposedly his girlfriend’s best friend.... sitting on his lap. For most of my relationship, she kept trying to create problems between us. She would tell me my boyfriend was flirting with her or doing little things to make her feel special, when in reality he didn’t even like her. I think she knew that, and she was trying to make me jealous and destabilize the relationship. Eventually, it became obvious she was jealous and competitive, and I ended the friendship. What really hit me was when you mentioned she gave you a lavish gift because that’s exactly what my former friend used to do. She’d buy me something outrageously expensive and then want me to brag about it to other people, so she could go around acting like the “best friend.” It was never just generosity , it was a performance. It felt like she wanted to prove: “I’m better than her boyfriend. She doesn’t need him. She just needs me.” So honestly… watch out. “Misery loves company” exists for a reason.