Funny thing about that is that this is what I responded to that I was quoting, so it's not an answer to what I said since that wasn't answered.
Quinn and Vinny having a relationship, whether serious or just fuck-buddies, whether public or private, is a Schrödinger's cat; we can neither prove or disprove that they were or weren't in a relationship of some sort. However, it is entirely possible that they were, and that's the point. It's fair game to speculate that there was something between them, particularly when there are some things that could indicate it.
And that's the thing, normally she's probably able to keep a good lid on that sort of stuff, but the MC has really got under her skin in a way that other guys seemingly haven't and it's resulted in her apparently talking about him often, even if it's not in the friendliest terms.
With Vinny, there may have been a more mutual understanding thus meaning that Quinn didn't dwell on him so much that she talked about him a lot, or she may have treated it as nothing more than a bit of fun like how many of the other girls seem to treat their sexual partners. So if Quinn ever talked about Vinny, it was probably the same way she talked about Tommy or Rusty.
It's entirely possible that Sage doesn't say something like that because, as far as she's aware, there's nothing to say here. Maybe if Quinn and Vinny did have a thing, it was just a FWB situation or they treated it as such and so nobody thought anything more of it. To Sage, this could very well be the first time she's seen Quinn behave like this with a guy because she never outwardly displayed anything similar with Vinny.
Also, whether Quinn was indifferent to the relationship or not, her continuing to hang out with the DIKs and be friends with Tommy isn't at all strange. They're top customers because of their parties, and even if they weren't much help to Vinny, it would be one of those situations where you can't really do anything so I don't think she'd have much of a reason to hold any sort of grudge, especially if it was entirely Vinny's fault and she knows it.
