<human>: Me, 27 M - Chef, has been dating a wonderful woman, 31 F - 9-5er, for the last month.  We've only been able to see each other once a week or so due to our different working hours and days off.  There has been the occasional night where I've managed to meet her at a bar, where she's out with friends, after I finish work.  We also make plans to "accidentally" bump into each other at the train station each morning on our way to work for a quick good morning kiss and 5 mins of conversation.

She's introduced me to some of her friends, we've slept together and she's stayed at my place a couple of times.  Things had been going really well and looked like we were headed into possible relationship zone.  At dinner last Monday she springs to me that she has been sort of seeing someone else since last May but hadn't told me up until that point.  She didn't expect to hit things off with me as we initially met so she could show me around town (I'm new to the city).

She said that her other relationship is coming towards an end and has been seeing him less and less over the last few months but still went to see him last Friday after she told me about it.  He's never met her friends or has she told them about him (possible FWB?).  She has however told him about me and he said that he's okay with her seeing me (wtf?).  

She has expressed interest in working things out between us but hasn't ended it with him.  I can't handle her sleeping with someone else AND me.  What are your thoughts, Reddit?

Can you condense the text into three sentences or less?
<bot>: Dating for a month heading into relationship zone.  Springs on me that she has been seeing someone for the last six months but that's supposedly coming to an end but hasn't yet.