Just More Guy Probs

Ok so... I dated this guy for a few months in like may June and July. About a month after we broke up he asked if we were still friends and I still really liked him so I said yeah and we were friends. About a month after him and one of my friends started going out and now they’re dating. I know it’s wrong but I’m so jealous because I really do like him so much. Every time they’re together I get so awkward because of him and her and my friends don’t stop talking about them together. I dont want to tell him how I feel bevause I don’t want to hurt him or my friend but it hurts every time they’re together. What should I do???