Looking for this cheating drama

I remember in the drama, there were 3 friends, a friend calls the remaining two to reunite and also invite them to his wedding. When she meets the guy, she goes in for a hug but he steps back and refuses.

I also remember at the end of the episode, despite her having a boyfriend, she sleeps with this friend because he earlier confessed to loving her and not being able to stay in  a relationship because of her