SML tries to be wingman for ML, but it backfires

The ML likes the FL so the SML tries to be a good friend and set them up. Except it backfires because it turns out the FL likes the SML instead. She begins pursuing him while hurting the ML. The ML and SML's friendship falls apart. Eventually the FL realizes she likes the ML and begins pursuing him, but the ML thinks she only likes him out of pity and that she still likes the SML.