This guy's honestly kind of a one trick pony, but it is a hell of a trick.

Why would you even bother to learn how to fetch the ball when you can do a triple summersault?

i dont care about the pony thing!

I saw some other pics from this series in the work of a guy called Murasaki Syu. I presume he's the same guy behind Activa. Practically none of his stuff is translated and most of the rest of it is pretty hardcore, but it all generally adheres to the exhibitionism theme.

Some of his older works aren't so great artwise and there's usually some other artist's crappy stories mixed in with his doujins, but one recommendation for his work would be the Hooliganism - Exhibition DX series. I'd warn again that it's pretty hardcore, but if you're getting off on stuff like the pic above it has still fundamentally the same appeal. As for tagging the rest of the pics, I am pretty much a leecher and a n00b on this site so currently I can't be arsed (I'm not totally sure I am correct yet anyways, some corrobation would be nice). I will just leave this long-ass comment here for now.

I don't think it's Murasaki Syu, the artwork is a bit different, and Syu loves sketchy lines and lots of sweat.