I had an EA a couple of years ago. Marriage isn’t unhappy but had become stilted as they do and I felt lonely and a bit dead inside. Along came colleague (also work in a niche industry) and he was like a breath of fresh air. I guess we bonded because we both have the same passion and interest at first but it was like you said, bloomed into lots of long conversations and I definitely felt the magnetic spark and attraction from the off.
Noticed the lingering looks, leaning in towards me, looking at me when I wasn’t looking then averting when caught, laughing way too OTT at my jokes, massively bigging me up to our other colleagues constantly, getting clumsy and fumbly around me. All the body language was there and I just became hooked.
Like you, I was handed the same lifeline when he was made redundant (our industry is notoriously unstable right now) and he got a job in his home country. We were both married with kids and decided this should be the end. Well, initially we said we’d stay in touch and we did email each other a couple of times but then we finally admitted feelings and decided to stop contact. Nothing physical happened beyond hugs.
I miss him still and it’s been over a year. I told my DH a few months after the email because he kept asking me what was wrong and I just decided to come clean. He was understandably gutted and we had therapy. I’ve stopped beating myself up now finally because there’s no point. I think about him and wonder what he’s up to but I wouldn’t reach out again, it’s better off in the past.
These things happen. It’s really easy for outsiders to sit in an ivory tower and judge because of course they are perfect and they would never commit such a heinous act. You haven’t really done anything other than start to fall for someone else. It isn’t ideal but you also haven’t acted on it yet. Use his new job as the blessing it is meant to be, stop contact and focus on your marriage if this is what you truly want.
I wish you all the best.