Friend's with benefits / Friend zone

I have been on and off with this girl for a while now and am interested in opinions on this.

We have worked together for almost 3 years, always very close and flirty work banter pretty much since the start from both. she broke up with her boyfriend before xmas last year and we have been hooking up on and off pretty much ever since. If we go out and drink it will end up in us making out or going back to someones, rarely actually having sex, normally just foreplay heavy petting etc. have had a threesome when both very drunk. Both went on holiday earlier this year together.

I was definitely "too" into her not long after we started working together and stopped seeing her outside of work as i didn't think anything was happening to pursue other people. Since we have started to hook up I've found it hard to place where we are. I am very aware most of the time things happen we have both had a drink and it might just be a drunk thing and nothing more.
There is undoubtedly chemistry between us, i think she knows if she sees other guys it will make me jealous, but we are not dating so she can really do what she wants. Every time I hook up with a girl and she hears about it the same thing works in reverse and she will be more interested in me for a while.

Maybe we're both stupid and can't commit to anything, or maybe I'm being blind, i have seen other people during the time we've worked together and don't have much of and issue going out and meeting other girls, I just like this one but don't want to overly emotionally invest in something that won't happen long term.



Cheers,

thoughts opinions much appreciated.