<human>: Can you give me a shortened version of the text?

I have a really good friend that we'll call Ashley. We were pretty much inseperable until she started this one guy, I'll call him Oliver. To make a long story short  they started dating and about 4 months into it oliver proposed and she said yes, this was about 8 months ago. 
Last night i went to a concert with Ashley along with her parents and a few mutual friends. Me and a mutual friend[mf] went to the bathroom (was pretty drunk so finding my way back to the group in the crowd alone was quite a task) and when i found mf after taking a leak she proceeded to tell me how her and Ashleys mom had been talking and they both agree i make Ashlee happier than her fiancé does, like to the point where they notice ashley is happier than normal during the concert. Mf then asks why i haven't made a move on ashley, i told her i just want Ashley to be happy. She reponded by saying 'so you're just going to stand by and let her marry the wrong person?' 
I didn't really know how to respond and i dont know how i should act on this whole situation, i really like Ashley and have known her for forever but i dont feel comfortable telling her this since she has a ring on her finger.
 Should i wait and see if Ashley and Oliver break up or confess my feelings to ashley??
<bot>: Close friend is engaged, mutual friends and her parents think i should be with her instead of her fiancé. I agree but hate the idea of undermining fiancé.