I think I'd like myself cute and hung.

Why overthink it?

Rimuru used [Universal Transform] to alter his body to give it the one thing it was missing: a fat hog. A burst of black fog erupted from his pelvis, his body expelling the magicules needed to add mass to his current form. And what a mass it was! The fog quickly dissipated, greeting Rimuru with the sight of a thick, meaty schlong that rested atop a pair of nuts that each had to be at least the size of his fist, if not a bit bigger. Cheeks reddening above his smile, he lifted it with his right hand to inspect it further. Recalling the memories of the most recent events that had led him to this point had dampened his arousal, explaining why he was flaccid now when he had been so worked up before he fell asleep.

Or maybe my state in the simulation isn't a one-to-one reflection of my state in real life? Nevermind, you can think about that later, you big nerd! More importantly, the weight of this thing is ridiculous!

He bounced his cock in his hand, enjoying the sound of the hefty slap it made when it landed back in his hand.

Daaaaamn! This thing's gotta' be, like, six or seven inches, and if I know my body, it's gonna' be even heftier once I'm hard! None of the humans in the city would mistake my human form for a girl again if they saw this thing! I know I was the picture of masculinity when I was human, but even ol' Satoru Mikami would have been put to shame by this! Is it possible to feel emasculated by myself? I dunno, but it's hot to think this thin, short, and cute slime guy Rimuru is probably packin' more heat than even a manly macho man like Gazel Dwargo.

"Eheheheheheheh," was the deep, motor-like laugh that rumbled out from Rimuru's throat. Now that he'd decided on what kind of body he should pleasure, it was time to think about what exactly he could do to the toys milling about in their camp below to bring himself that pleasure.