A/N: so my prunes T.A. and tayg evidently think I'm a whole different breed of crazy, and convinced me to fill a prompt about Mordin giving a random alien a prostate exam. Yeah… I did a D: at the screen, too.

So, this is a departure from my norm. It is nothing but silly toilet humour, with a 80% ish medically-accurate prostate exam thrown in at the end. If that's not your cup of tea… you've been warned ;)

And… because I am also horrendously embarrassed about having written the story, it may find itself taken down soon.

"What are you looking at, pyjak?"

Mordin's head jerked up, eyelids blinking rapidly. Wrex was glaring at him with those beady eyes, his body turned protectively to the side.

"Staring? Was not staring. Merely… listening… contemplating."

"You're listening to me take a piss?!"

"Yes, yes! Note with which stream strikes urinal very telling. Musical. Javik's harsh, bursting. Always disdainful of company, rushing to do business and leave. Kaidan more relaxed, flow rhythmical. Sometimes wonder from humming and sway of body if he times it to human composer Mozart while urinating. Garrus syncopated. Hypothesize from constant shifting and bouncing that turian plates get in way of… comfortable exposure of… appendage to outside environment."

Wrex's glare had been replaced by a look of slack-jawed befuddlement. Mordin, still whittling on, was, of course, completely oblivious.

"I don't even want to know, pyj–"

"You… hesitancy, weak stream, terminal dribbling at end… shaking off more than average krogan… very uncharacteristic. Wonder if…"

Wrex was desperately waggling his penis, trying to shake away the last dribbles of pee so he could leave Mordin to his sordid musings.

"Of course! Stupid to not think of earlier. Thought maybe crush on Eve, pressure of being first sire to fertile female offspring, performance issues…"

"I do NOT have performance issues!" Wrex's low growl was dangerous. If he wasn't still dribbling, and worried about the piss getting into his newly-cleaned armour, he would have broken Mordin's neck by now.

"No, no, merely discounting theory. Only plausible diagnosis… prostatic hypertrophy!"

Wrex blinked, stunned. For a moment, he lost his grip on his willy, cursing as it flopped downwards and pungent urine dribbled down the inside of his leg.

"Easily curable. But… need to confirm diagnosis."

"Prosthetic what?!"

"Common in old –"

"I am NOT old!"

"Age is fact, Urdnot Wrex. You… senior citizen by all definitions. Prostatic enlargement… not unexpected."

Wrex was silent, only glaring at the salarian in simmering anger.

"You can cure it, pyjak?"

Mordin sniffed, turning to wash his hands. "Of course. Urinary symptoms gone. But must confirm diagnosis before procedure."

"Fine. As long as it doesn't involve needles."

Mordin smiled knowingly. "No needles. Come, best to get it over with. Still have work on genophage cure to do."

Mordin looked at Wrex's gaping jaw in amusement, lost in his thoughts. Krogan temporomandibular joint not known to have such wide range of motion. Perhaps combination of fear and surprise induces ligament laxity. Interesting theory. Must test. Implications for fellatio and cunninglingus… positive.

"Procedure simple, Urdnot Wrex. Lie on your side. Time short. More important things to do."

"Pyjak, if you think I'm going to let you –"

"Choice yours, Wrex. Must work, so lie down or excuse me."

Wrex let out a low rumble, as he begrudgingly pulled his pants down, taking his place on the bed. "You sure those windows are sealed?"

"Yes. Do not wish witnesses to this any more than you do. Although… social implications on crew… interesting. Human and asari facial expressions most telling. Would enjoy implications of Lt Alenko –"

"Get on with it already, pyjak!"

Mordin sighed, grabbing the box of gloves and tube of lubricant lying on the desk. "How long since last bowel motion?"

Wrex coughed, half-turning his head as if to look at the good doctor. "Errr… I can't remember. It's been a stressful time, ok?!"

The salarian's shoulders sagged in dismay as he pondered the implications. Krogan faeces notoriously acidic. Must protect fingers or risk being more intimate with krogan than intended.

Gingerly, he put a second pair of gloves on over the first. "Draw knees up to chest, Wrex."

The krogan obliged, and soon, his fleshy behind, complete with an innocently flapping tail, was completely exposed for Mordin to see. A wide grin spread across his face. Those red marks…

"Interesting… numerous excoriations."

"What?!"

"Scratch marks… itchy bottom, Wrex?"

The krogan's angry growl was all the answer Mordin needed. "Possible allergy to underwear. No matter. Creams available. Just gently massage bottom morning, noon and night to relieve itch."

Mordin had seen all he needed to see. He squirted a generous serving of lubricant jelly onto his index finger, before placing the palm of his other hand on Wrex's butt cheek, lifting it upwards. "Deep breath, Urdnot Wrex."

When the krogan complied, Mordin swiftly inserted his finger, pushing backwards slightly to counteract the reflexive muscle contraction. Krogan sphincter tone high. Believe Joker would say "tight ass".

He grimaced as he pushed his finger in, the pulp running over craggy masses of impacted faeces. "Wrex. Highly suggest potent laxative. Rectal options more potent. Can give you suppository now if you –"

"Don't you dare, pyjak. Hurry up before I reach for my shotgun."

Mordin sighed, pushing harder. "Also suggest diet, Urdnot Wrex. Bottom padding… generous. Proper examination… problematic."

"Shut up, pyjak"

Just when he was certain he was going to tear his index finger off his hand with the pushing, Mordin felt the smooth ridge of Wrex's prostate. He swept his finger over the bulge, mentally sizing it, noting its smooth contour. To complete his examination, he turned his finger 360 degrees, leaving no part of the rectum uncaressed before swiftly withdrawing his finger.

Mordin glanced at the soiled glove, noting the colour, consistency and foul stench emanating from it and filing it away for future reference. "Krogan constipation different from other species. Usually odourless, but yours… charming. Lucky not in stages of overflow yet. Highly recommend laxative before leakage phase begins. Krogan in diapers… interesting theory, but unbecoming of clan leader."

Wrex, if not for his heavy panting, would surely have gutted Mordin by now. "What about the original purpose of this exam?"

Mordin blinked. "Oh. Yes. Enlargement. Simple. Correct, of course. Surgery easy. Come by later. Machine calibrated by then."

With a swiftness surprising for a krogan, Wrex leapt up from the bed, pausing only to stumble into his shorts, before dashing out of the room, leaving an amused Mordin to his thoughts.