There's this girl I met at my gym a few months ago. We go on well & became friends.

Anyway, there's this guy who works there. She says she chats to him and he's asked her out on a date a few times but she's not into so she kept saying no to him.
One day I was ill so I didn't go to the gym but my friend went and we were texting whiles she was there and after her work out she told me she was going to the guys office.

I didn't her from her after that. She stopped coming to the gym I asked her why and she says she's been busy with work. She also texted me saying she has something major to tell me.
She hasn't told me yet and is been about 2 months now cause I don't see her.

This guy has been flirting with me and he's asked me out on a date on Sunday. Now I'm starting to like him he makes me smile.
But I don't want to go on a date with him if he's done anything with my friend.
I think something happened with her and the guy that's why she stopped coming to the gym and that's that something major shes gotta tell me.


How do I find out if anythings happened between them?

What should I do? Should I go on the date or not?