I have always been hesitant telling people about my experiences with my Granddad, I did confide in a few mates who thought it was discussing and I got the feeling they thought I was too but others thought it was really hot much like the sentiments in this thread really.
It happen when I was 16 and ended when I was 18 so don't go thinking he was a wrinkled old man with grey hair because he was only 55.
Generally mates I've told have presumed he was gay or Bi but to honest he was neither just a bit of a dirty bastard (well a big dirty bastard) so I've never been able to label him. He was a regular bloke in a regular job who drank pints of Bitter with his mates at the Labour Club a few times a week so there is nothing to pin on him as being gay or Bi, he was just permanently horny and didn't care how he got his rocks off. I would say he was very much a mans man so really he identify himself as straight in that sense.
My friends who thought it was nasty also presumed he baited me or groomed me but that was not the case either, I initiated it all the way.
The experience didn't fuck me up or make me a sexual deviant and I haven't felt the need to go seek therapy and although it was quite a few years back now I can only say it was one of the horniest things that has ever happened to me and I'm glad it happened. The only thing that has lingered is my preference towards older dad types and I do attribute this to Granddad probably because I was young and impressionable but other than that I'm normal (as normal goes).
I would never condone under-age sex in any form but in my case I was of legal age, already sexual active and knew what I was doing and I do think there is a huge difference in that.
Because some of my mates thought it was nasty I initially didn't tell my husband but a year ago I spilled the beans and thankfully he fell in the 'OMG that's so horny' camp and yes he's 10 years my senior Ha ha!