If fellatio is derived from "fella," which commonly means "man" or "boy," with the -tio suffix added onto it, then I think the equivalent for women's penises would be ladytio.

Think about it! You ever hear the song "Hey Ya!" by Outkast?

In the iconic bridge, he divides the attention between "fellas" (men) and "ladies" (women).

Hey, all right now, all right now, fellas (Yeah?)

Now, what's cooler than being cool? (Ice Cold!)

I can't hear ya

I say what's, what's cooler than being cool? (Ice Cold!)

All right, all right, all right, all right, all right, all right, all right, all right

All right, all right, all right, all right, all right, all right

Okay now, ladies (Yeah?)

Now, we gon' break this thing down in just a few seconds

Now, don't have me break this thing down for nothing

Now, I want to see y'all on your baddest behavior

Lend me some sugar, I am your neighbor

Ah, here we go!

Remember, André 3000's words are the highest degree of credible you can get, so my answer must be undeniably correct.

I'm sorry that you said "Wrong answers only," but I'm a bit of a rebel. You're gonna have to get used to it.