Wanna cheat on my gf

Hey 19M here, i have been in a relationship from 2 years but the girl am with is making the relationship too toxic and is mostly with her guy bstf, she isnt fulfilling my needs both mentally and physically. Other than that now we are in long distance and there's literally 0 fun left as she is mostly with her guy bstf and am pretty sure they fucking. So yeah i wanna get some action too, make a fwb whom i call my girl bstf in front of her and turn the tables on her. Dm me