I don't know that I woudl ever seriously enter a relationship with a girl who still had an attachment to an ex, unless it was thru kids, which you'll never outrank.
if she worked with him, still ran with that same circle of friends... unless she had solid gold tang and shot gold bars out of her ass, I'd probably keep moving. Too much drama.
I've seen lots of girls who keep their ex's all close... they never find a satisfying relationship. The new dude is ALWAYS drinking to cope within a few weeks of that crap.