He cheated.. now what?

So I have a friend that i work with, she's extremely into this guy we work with. To my knowledge, he's into her too but he denies it to anyone that ask. Long story short, they slept together, he had a girlfriend but they broke up for other reasons, supposedly and now my friend is just waiting in the distance. I'm not sure if he said they would be together but he's running around telling everyone he's single and he wants to stay single. Now he completely denies even being into her and he's switching his work schedule around to basically not see her.

Granted im only asking because she's confused and I honestly have no words. I don't speak to the guy otherwise I would've asked myself what's his deal but it's also suppose to be a secret between them so if anyone brings it up she's really screwed with him. Anyone have suggestions on what she should do or anything?