Welcome to the boards. I can empathize with you as I had 2 occasions in my past 4 years of dating (since my divorce) that something similar happened.
2 really nice guys, 2 insecure controlling women (one a wife, one a gf). One date, lots of sparks, intimate talks, lots of flirting, some physical contact (sex with the first one, holding hands and kissing a bit with the second), requests of 2nd guy to FB friend him, hormones of NRE rushing through my veins.
The 2nd guy, M, was more recent. I'd known he and his gf had had a shared gf (unicorn) just a few months previously. Said unicorn had had a big blowup with his primary and broke up with them. I'd told him I don't date couples when we'd been IMing before meeting and he ran it by his gf, who said, go ahead. (I wasn't attracted to her-- I'd looked at her ok cupid profile and pix.)
Well, soon after our date, M told me she told him he couldn't see me anymore. This woman was friends of friends of MY bf and he'd FBed M too. I took M off my FB after he bailed, but my bf stayed on his list and he was my spy, heh. He told me a month or so after I'd met M, his gf broke up with HIM.
Anyway, I was disappointed, I did feel bitter, but luckily after 4 years of dating, coming across fools and cads from time to time, I got over it pretty quick. I hope you do too. And I hope you find a better guy sooner rather than later!
Love withers under constraint; its very essence is liberty. It is compatible neither with envy, jealousy or fear. It is there most pure, perfect and unlimited when its votaries live in confidence, equality and unreserve. -- Shelley
Mags (poly, F, 61) loving miss pixi (poly, F, 39) since January 2009, living together since 2013
"Master," (mono, 34), miss pixi's Dom for 2 years