Advice Needed Relationships Question

Alright, so I liked this one girl right, but the thing is she has a boyfriend. For the most part Ive moved on from liking her but like the thing is thats kind of hard when she comes over/we hang out at least 2 times a week and constantly talk. She tends to be naturally kind of flirtatious and like she said that she led her boyfriend atm on for a bit before getting with him but like Im not gonna chase a dead end right.

See now, the thing is, Im lw eyeing her best friend right now and would it make me seem hella desperate if I were to try and get at her? Her best friend doesnt have a boyfriend so its an available opportunity