You i tell her to f*** of?

Ok so i work with this girl that to me its super weird. She has only been to one party with my bf and tells me that she sees him at parties getting trashed all the time. She tells me shes not going to a party and i find her in the back at work calling him for direcrions and when shes on the phone she tell me yea im callong your bpyfriend, he didnt invite her to the party someone did. She texted me to ask me where he was cuz she was wondering she was also with another girl. She ended up going to lunch with me but i left for and the 3 of them hanged out. I see her at work days later and she tells me she try some cigars of my boyfriend. Like 3 months ago thw 3 of us were sitting on a bench and her knews were really close to my boyfriends.what should i do????