There's a fairly obvious functional difficulty with the drive behind this battle-cry. The esteemed grade-school sexkittens of the caller's torrid imagination might, in fact, be expert in Powerpuff-enhanced acts of sexual predation, depravity and (heh) skill; however we will likely never see them.

But WHY? I hear the cry.

Simple. Unless your taste runs to implied representations of fisting or something similar, the poor Girlies can't do anything for you. Look at them. Look at 'em, man! (And woman!) They:

Now, I'll admit, the first and fourth points are only relevant to matters of personal preference, personal physical compatibility and possibly local statutes involving sexual acts with a super-powered minor. The second and third, however, are the crux of the matter, man! How do you suggest the Powerpuffs perform said acts? Let's look at a small sample and their compatibility issues.

So what is there? Sure, you could use their little mitts for manual activities (heh) but that really don't seem hentai to me. Nope, looks to me like the very nature of the Powerpuff Girls defies their typing into hentai roles.

Now, I'll admit, I'm not a hentai aficionado. So there may, in fact, be practices common and exciting to and in the hentai community that I have not mentioned here. If you're one of those and can enlighten us, please, do! It's all about education, and you never know when you might come across a drunken Bubbles in the park one night, mean shitfaced on root beer mixed with Bottle Caps, horny and lookin' to score. If that happens, given the little lady's on-screen persona, you best be able to think of something she'll enjoy...and I don't think the fellatio option will count, nope nope.