I’m not sure if I should be posting in Sex or Relationships really, or what I want from posting beyond someone to help me see a way forward here, but here goes...
A while ago I developed a crush on a coworker. It became apparent it was reciprocated but neither of us mentioned it. I just got a bit of a buzz at the office and would come home feeling rather sexy. I tried to channel the energy back into my relationship with DH, which had been a bit stale sexually, and all was good.
However, DH gradually started to pick up on my crush - we’ve been together a very long time and he knows me too well! He has a history of being a bit jealous (cheated on by an ex) and he didn’t take it too well, but I reassured him it was nothing serious, I loved him and I had no intention of doing anything. Still all OK.
Fast forward to more recently - my crush hadn’t dissipated and I had to go on a several day long business trip with the coworker. I was nervous and DH enjoyed teasing me about it a lot before I left. Strangely he seemed more excited than annoyed about it, making lots of references to what might happen, and getting quite turned on. We ended up having v passionate sex the night before I left, which involved him talking about OM doing things to me 
On the trip OM and I had to spend huge amounts of time together and - especially after the sex with DH - I did feel v attracted to him. I’m pretty certain he felt similar. I managed to avoid embarrassing myself, although late one night after celebrating a work success I suggested he come to my room for another drink (the bar was shutting). I don’t THINK I had any intention of actually doing anything stupid but it felt very risky. Thankfully OM told me very nicely that I was too drunk to make that suggestion and should go to bed. I did.
Here’s where it gets even more messy - since I came back from the trip DH and I have got it on every night, sometimes several times a night, and the unwitting OM has become a centrepiece in what has become a very exciting and adventurous sex life. We have never been like this before so it is a bit of a shock! However, as part of sex, DH has several times asked me about what happened during my trip and I’ve found myself embroidering increasingly salacious details for his amusement. I don’t know if he believes me or not but it is certainly putting a rocket up our sex life.
The really messy part is that I still have to work with the OM, who is of course unaware of all this. I can barely look him in the eye! It doesn’t help that I’m still attracted to him, and since the night I almost propositioned him he has been paying me a lot of attention. I am now scared I will actually end up doing something stupid like jumping on him in full view of the board of directors and probably getting the sack.
I don’t know if I should confess to DH that I made up most of the “details” of what I got up to while away (I think he probably guesses it’s not all true), and avoid the OM as much as possible - or embrace the great sex and damn the consequences. I must say that I am selfishly reluctant to go back to once-a-month sex with the lights off, which is where we’d ended up before this.
Please be kind - I am genuinely in a right fluster. Apologies if this is all a bit sordid. It is most unlike me.