Friend lied about crush

A few months ago, I finally told my crush I liked her, we work together. She politely turned me down saying she had just got out of a relationship, and I told her no problem. I understand. Next, she starts commenting about how hot this guy is. I already had suspicions she was with my best friend, he denied it several times. And he knew I liked her, for quite some time. After a while it became pretty obvious, and I don't mind. But they both work at my job and keep pretending they're not together, laughing at me behind my back. Now they've gone on a skying trip together with her friends, and he's pretending to not be there when I have recognized his car in the photos. Both of them have also blocked their photos from me on Instagram. She told me she had deleted her account, and she hasn't of course. I thought they were both my friends; we've known each other for years. And never expected them to do this. Especially her, that's why I finally got the courage to ask her out. To be honest I don't mind them being together, it's the mockery and lies that bother me. And they wonder why I become distant, but what else am I supposed to do? #cheating #infidelity