I've felt it a few times in my life.
Sometimes it's led to a relationship & others a shorter 'fling' and other times nothing at all other than daydreaming.
I was a newly wed, in love with my gorgeous new husband who was away for a couple of nights with work. During this time in my work we had a project partner visiting from Switzerland & it was my job to liaise with him as the project manager
The minute we set eyes on each other there was a frisson. We both felt it. I caught him looking at me when he didn't know I could see him. We entertained him over a dinner & went for a drink after & he sat next to me in the pub. It was a booth / sofa type seat with a table in front & single chairs. I sat on the sofa & he sat in beside me & our thighs touched & honestly I almost physically jumped.
I shuffled a bit to move away but others came & we squished in a bit & his leg rested against mine & I let it. And I can vividly remember never being as aware of my own leg & the feel of his in my entire life.
He had beautiful hands & I also remember actually fighting an urge to touch his hand as it was on the table beside me in the pub. And feeling super guilty for feeling that way.
Obviously nothing happened. A single colleague attached herself to the group & spent the night shamelessly flirting with him. He went to the toilet at one stage & she commented on what a great body he had & how she hadn't noticed till he took off his jumper & she saw him in his tshrt I felt jealous though I had no right. And I had noticed his toned arms immediately But I remember him regularly turning away from her to say things quietly to me. Nothing untoward or even flirty but I felt the force of his focus which he wasn't giving the other girl.
When it came time to say goodbye we hugged. It lasted just a fraction too long. Enough to know. Honestly I could have kissed the face off him there & then & I don't think he would have said no.
I knew it was trouble for me so when he visited one further time for the project I made sure I was busy on another project & was nor involved in his visit. We did see each other in my building & we greeted each other & I felt myself blushing & fearing that all my colleagues could see though me & would know my filthy thoughts about him.
I never met him in person again though he became well known in my sector & I loosely follow his success over the years. He's still v handsome from the photos in the media I've seen.
I have absolute certainty that he felt the attraction / chemistry too.
I'm still married to my wonderful husband 20 years later & have had / am having a fab life with him. And I rarely think about Mr Switzerland anymore.