Happened about eight years ago when I was 50ish
I had split from my wife of 20 yrs and been on my own for a couple of years. I had purchased a new computer and although I was new to the internet I came across quite a lot of contact sites for swingers while looking for wanking material. I was so excited about what I had found that I just had to answer an ad to a fairly local couple that were looking for a male to join them for threesome sexy fun. To my surprise they were interested and we met at a halfway pub for a drink and chat. We got on well and arranged for me to go to their place a week later after 9-30pm as there mother they were caring for went to bed then. I arrived at their place and we had a drink and got down to the sex part. Anyway I met them every couple weeks for a few months then one night when I went there we went to the bedroom and got down to business as usual when after I had just cum on this guys sexy wife she whispered in my ear would I help her with her fantasy. I said depended what it was but I'm open minded. She said she wanted to see her husband being wanked off by another guy. So after thinking about it for a short while I said yes I would try for her as never done anything like that before. So I reached across and took his circumcised limp cock into my hand and started to fondle it. To my surprise it was very soft and velvety and it was only a second or two before I could feel it getting harder in my hand mmmmm nothing like I had imagined and I could feel my own cock getting an instant erection and I couldn't believe how turned on I was getting.
Anyway I was stroking his cock up and down gently at first and a little harder as I went on. His wife was watching at very close quarters with her mouth open and about a foot away from his cock and my hand. She was getting really turned on and I put my other hand behind her and felt her pussy inserting one finger. Wow was she wet still from five mins earlier but as I looked down at her shaven pussy I could see she was dripping juices out of her which I've never seen before. She said god I'm sooooo turned on keep wanking my hubby please I love it. So continued to stroke his hard cock up and down harder and faster as he was breathing heavier as he was enjoying it more and more. She cupped his balls and had her mouth open ready for when he was about to cum so I went faster and faster until he shouted god I'm cumming when she suddenly put her mouth right over the knob end just as he came. It must have all gone inside her mouth and she swallowed it almost immediately. She then asked if it was ok for him to try wanking me off but by this time I was sooooo horny I said please pretty please and he started to wank me. It was his first time with another cock too so he wasnt that good at it but it was still nice. I had one hand between his wifes legs fingering her sopping wet pussy and the other playing with his semi hard cock about 5' while he was gently trying to get a rythmn going wanking me. After about seven minutes she asked if she could wank me as she liked my cock as it was about one and a half inches longer than her hubbies. So she ended up wanking me off and he ended up with my cum in his mouth as she made me cum not a lot as most went into her pussy half an hour earlier.
That was my first experience of wanking another guy off and I thoroughly enjoyed every minute of it but unfortunately haven't had a great deal of fun with another guy since other than a little touching within another threesome I had. Can't wait to wank another guy sometime especially if their female partner is present.