Formaldehyde wrote:
Anyway, when I say that my friend introduced my to her a couple of months ago, I mean that that's when they first started going out, it wasn't a multi-year relationship or anything like that. As well, he is quite the charmer and the ladies' man and I'm pretty sure has already healed for the most part, pretty sure he hooked up with another girl at the party we had.
This could change things a bit. If your friend wasn't that serious about her and is one of those guys who goes through women fairly quickly, you might be ok. Unfortunately, these situations can lead to the friend saying they're ok with you dating the ex when in actuality they're not. That's why I usually advise people to just stay away from friends' exes.
The problem here is that your situation really requires being able to read between the lines. People with AS can have difficulty with doing that. Since we're talking about your best friend here, you need to think carefully about if this girl is worth a breakdown in your friendship with him (regardless of whether he says he's ok with you dating her or not).