Mine was my 'childhood sweetheart' together through our teens, he joined the services and moved away, we stayed in touch throughout the years. We connected again romantically in our mid 20's but the timing was terrible, I had not long left a violent relationship. He asked me to marry him and I said no because I needed to be by myself.
My intentions were good but it hurt him as I don't think he totally understood my reasoning.
We're old friends now and i have him on SM, no bad feelings between us. I think we'll always care for one another in some way but anything 'more' is long gone.
He has recently gone public with his new girlfriend and they look so happy, she's a stunning woman and I haven't seen him so happy in years.
Seeing this is bitter sweet because on one hand I'm genuinely pleased he has found somebody good for him and wish them nothing but the best as a couple, but I can't help but feel a bit sad and wish I had given him a different answer those years ago.
I've had to quietly unfollow (not unfriend) him so I don't keep seeing pictures of the pair of them.
I have a family of my own so I wouldn't dream of letting him know how I feel, let alone betraying my OH, but it's just feelings isn't it.
Do you have a 'one who got away'?