Roommate Flirting Issues

I’m a freshman in college and just got out of a long, tough relationship. I am loving my freedom and the friends that I’m making, but I’m developing a slight resentment for one of my roommates. She’s stunning, curvy, and so fun to be around. She also has a committed boyfriend who is twice her age. I really value her as a friend, but lately she has been trying to - for lack of a better phrase - steal my thunder.

I’ve had sex with this guy twice and I have a mild crush on him (she is aware of this), but she’s constantly texting him, flirting with him, and almost showing off herself to him. The other night he said in front of a group of our friends that she has his “ideal body type” and confided in her about some personal issues of his. This stung for obvious reasons.

This kind of situation with her has happened before, both with friends and lovers of mine. Should I talk to her? Should I let it go because I’m being a brat? Should I chat with the guy about this? Please help!