What Difference Does It Make?

I glanced at him and saw that he was checking out my cock, just as I had his. I wasn't surprised or embarrassed: in my experience of being naked around other guys, it's a pretty normal for them to compare each others' kits.

And, in any case, he was probably wanting to see what his big sister was getting served up.

I bent to pick up my towel and noticed him check out my backside too. Not quite so normal, but still in no way odd.

I turned back to face him. He glanced at my crotch again and was no doubt mentally comparing his hefty balls with my own. Although I've always thought of my balls as being quite a comfortable size - about as big as a pair of walnuts - they looked pitifully unsubstantial up against his. 

I looked down at myself and then back at the front of his briefs. It was pretty clear that, even if my balls weren't any competition for his, I was the out-and-out winner in terms of cock size. Mine was five or six inches long, even though it was limp, and as thick as a carrot. His looked like an earthworm in comparison.

He said, "The shower's pretty straightforward. The outer dial controls pressure and the inner dial controls temperature."

I nodded. "Sounds okay..."

"I just thought I'd tell you because the writing's worn off the dials."

"Cheers."

Then he turned and bent over to get a pair of socks out from the drawers beneath his bed.

I'm sure it was unintentional, but the way he stuck his arse out towards me really took my breath away. His legs were wide and his knees were slightly bent; his back was bowed and his arse was thrust towards me with the cheeks splayed open inside his briefs.

I think I might have gasped.

You see, that's the pose that his sister is very adept at assuming when I fuck her from behind. The exact same pose being expressed by her brother.

I was unable to stop myself from mentally picturing myself fucking him. Walking up behind him, pulling down his grey briefs just like I did with his sister's white panties, and driving my cock into him. Pushing myself into his arsehole just as I would penetrate his sister's pussy. Relishing the pungent odour of his anus as I entered him just as I would the sharp scent from Kaz's vagina.

I wondered if he would whimper and cry out like Kaz did when I fucked her. Whether he would want me to reach round his chest and play with his nipples like his sister did.

Before I knew it my cock was rising to life, almost poking into the back of his briefs as it lengthened and thickened in front of me.

Michael stood up and turned back toward me. I quickly came to my senses.

He glanced at my cock, now almost fully hard, as I struggled to wrap a towel around it and my waist.

He smiled and I felt myself turn scarlet.

I grabbed my shampoo and hurried out from the room.

I couldn't make my erection subside while I showered. No matter how I tried to redirect my thoughts, the image of Michael bending over and thrusting his arse towards me kept returning to my mind. My erection would pulse upward with even greater vigour.

In the end, I gave in to its insistence and roughly wanked myself beneath the spray of the water.

I was trying to visualise myself fucking Kaz from behind, but my imagination would keep overtaking me. Without warning she would metamorphose into him. I'd find my cock sliding in and out of his tight, pink arsehole. My balls thumping against his larger, rounder ones. My fingers on his flat chest, teasing his erect nipples. His voice, not hers, urging me to continue.

I fought to reject the mental picture of him for a while and then gave in; accepted that it was him that I wanted to fantasize about and put it down to "healthy sexual intrigue about a girlfriend's sibling". I was sure I'd read about something like this in a textbook. It was perfectly normal; not an authentic gay desire at all.

I quickly finished masturbating with the thought of him reaching his orgasm while my cock drove in and out of his splayed buttocks bringing me to completion.

I was careful to wash the splashes of my semen from the wall of the shower cubicle.

Nothing else of any significance happened between Michael and I until after the meal with the uncle and aunt. There were a couple of knowing glances across the breakfast table after I'd finished showering and dressing, and a repeat of the fairly obvious crotch comparisons over the following couple of mornings, but nothing major.

The main event - and, as it happened, the start of an stimulating friendship between Michael and I - began when we'd got back from the restaurant.

I'd noticed that Michael had been drinking far more than a guy of eighteen ought to, even one who has just experienced his first term's drunken revelry at University.

The fault could mainly be lain at the door of his uncle: he'd been going on about how he hadn't had a "legal drink" with his nephew yet and that this is what he'd been waiting for since Michael's christening. So he kept getting extra drinks for Michael despite Michael's mum's disapproving glares, plying the lad with pints of lager followed, as often as he could get away with, by whiskey chasers.

I suppose the uncle probably just wanted to loosen Michael up a bit: Michael was clearly uncomfortable about socialising like this and spent a lot of the time in contemplative silence.

I could see what the uncle was trying to do, but it didn't seem to work.

The alcohol just made Michael sullen. He'd glance over at me and seem to resent the fact that I was having a reasonable time, enjoying the company and chatting freely. Or maybe he was annoyed that no-one was talking to him.

It only became clear that Michael had had way, way too much to drink when we got up to leave the restaurant. The poor guy could hardly walk; he veered around the restaurant, almost colliding with other diners, and had to use the backs of peoples' chairs as support.

Kaz's father and I helped him back to the car, while Michael insisted loudly that nothing was wrong.

We had to pull into a layby on the A65 for Michael to be stumble out and be sick. I went with him; the rest of the family pointed out that I was a trainee medic and so it would be "good practice".

While he threw up, I put my hand on his back to let him know I was there. His skin felt hot through the material of his shirt and jacket.

He muttered, between surges, "I'm really sorry about this, Seb. I didn't want you to see this..."

I said, "Don't worry about it. I've seen a lot worse..."

When we got back to the house, Kaz's mum told her dad to sort Michael out and put him to bed. Her dad looked queasy.

It was Kaz who suggested that I "might like to do the honours". I think she had meant it as a joke.

But her mum looked at me brightly and said, "Ooh, would you, love? It'd be ever so good of you..."

I couldn't really say no.

I went to the stairs and found Michael splayed out halfway up.

I said, "Come on then, mate. Let's get you up to bed..." and helped him to get up the rest of the stairs. I think I noticed that, as Michael used me for support, he kept touching my thighs and would sometimes brush his hand against my crotch, but I never thought much of it. The lad was paralytically drunk; he didn't know what he was doing. Or so I thought.

I got him into the bathroom.

"Do you want to be sick again?"

He drawled, his voice husky and the words merged into one sound, "No that's passed."

"Well you better wash out your mouth and brush your teeth. The acid from your stomach will burn the enamel off them in your sleep..."

He raised his eyebrows in surprise and then tried to focus on his toothbrush.

I did most of it for him. Passed him a glass of water and watched him rinse his mouth, put paste on his brush and watched while he clumsily poked it around his teeth, and then refilled the glass for him to rinse again.

Then I told him to drink a couple of glasses of water to ease the hangover he'd be feeling the next day.

I joked, while he drank the water, "If you end up being my brother-in-law, you're never gonna live this down, mate..."

He smiled. "You'll have to remind me, then. I never remember anything when I get like this..."

His words sounded a lot more coherent.