"In case you hadn't guessed, Gee and I have a very open marriage, don't we love?" smiled Val, my badminton tutor, putting her hand under her husband's chin. "And my gym is where we can let off steam in a very healthy way! Now I'll just go and have a quick shower, so why don't you show Andrew all this equipment? And Gee - you've still got your gown on! Cardies only please! - we can't have the host disobeying the rules now can we?"
"But I've got my cardy on under the robe, Val," he said, undoing the belt and slipping off the robe as he moved away towards the wardrobe.
He was wearing a thin black cardigan - it must have been one of Val's - buttoned up to the neck, with tight pale grey underpants, clinging to his bottom as he walked away. Then he turned round to face us, calmly smoothing down his cardigan and putting his hands on his hips. I was still sitting naked on the floor, and couldn't help notice the sizeable bulge at the front of his underpants as he stood there in front of us.
I didn't mean to stare, but you could easily make out the shape of his cock through the clingy tight fabric of his underpants, which seemed to be lying semi-erect to his left. I couldn't help wonder if he'd been listening as his wife had been having sex with me - and that's why his cock was now getting stiff. Then I had another though about Val's rules, and suddenly felt very uneasy.
Val had moved to the door now, but looked back at him with a frown.
"Er, Gee - aren't you forgetting something? You've still got your undies on!" said Val, opening the door. "Now strip off those underpants and show Andrew around the equipment. I've given him a good initiation but still needs to know what all the gym equipment is for, so why don't you show him around a little while I shower? I won't be long but I just need to freshen up after all the spunk Andrew left inside me!"
And with that she was gone and the door clicked shut. Suddenly I was acutely aware of the two of us alone in the room, me naked, and sitting up to hide myself a little, but Gee moving over towards me, black cardigan and grey underpants still on, and that bulge getting bigger at the front.
"I hope you enjoyed your warm-up," he said, pulling his underpants up slightly at each hip. They were a plain light grey, very smooth stretchy cotton, cut away so that at the hips it was just a broad elastic waistband, with a neat thin black stripe. It was as if he liked showing off his pouch in front of me.
"Val's very good with her exercises, isn't she?" he asked, looking down at me sitting on the floor, as he started to unbutton his cardigan from the top.
I wasn't used to seeing a near-naked man this close, especially undressing in front of me, but felt I had to say something as I wiped the last of my cum from my cock, knowing it had been inside his wife so recently.
"Yes, she's certainly very athletic and must be very fit."
"Oh she certainly is that - I can't keep up with her, that's for sure." said Gee, now standing with his cardigan open just in front of me. "Well up you get - and put those dirty tissues in the bin over there." He pointed to the corner of the room.
I rolled over, still half hiding myself, till I realised he could see me from all angles in the mirrors anyway. It felt so bizarre and wrong as I stood up, naked in the room with Geoff wearing just his wife's open cardigan and his own bulging underpants.
I put the tissues in the bin, pretending it was just an ordinary thing to do, and as I turned round I saw he was pulling his underpants down, then dropping them to the floor. He bent to pick them up, then grinned and moved towards me holding his pants, to put them in the wardrobe. I didn't mean to stare at his cock, but it was just there, hanging down, half erect and uncircumcised, bouncing with each stride as he walked. I noticed he also had a little necklet around his neck.
"You needn't worry about staring at my cock - you'll have plenty to see here in the Gym when we all get going!" he smiled. Gee was quite close to me now - only a couple of feet in front of me.
"Here, let me see you a bit closer - it looks like you've got a good length there!" he said, and just reached forward and put his fingers under my now sagging cock, squeezing me gently and pulled me slightly towards him.
It felt just so outrageous when his finger first touched me, and my cock twitched involuntarily with pleasure at the awful sensation.
"Yes, that's a very good one for a youngster - nice and strong too!" he said, staring at my cock now held in his hand. "I bet Val enjoyed having this up inside her."
I felt so outraged and embarrassed I didn't know what to do. Almost as a reflex I just reached back at his cock, and held it too. It was so thick at the base, and warm, but not that long - at least not until I touched it. He looked me in the eye, still holding and squeezing my cock which was now growing by the second in his hand.