From John Baker yesterday, this strip from the webcomic Punch An’ Pie:
Baker explained that Punch An’ Pie (by Aeire and Chris Daily) is a
webcomic that follows the lives of several attractive and not terribly prosperous young people. In the linked strip, the shorter woman, Angela, is the manager of a toy store, and the other woman, Karen, is one of her employees. Karen admires Angela and recently learned that Angela is bisexual. This led Karen herself to experiment sexually with her best friend, Natalie, who is also an employee at the toy store. The experiment was not a success, and Karen now feels uncomfortable around Natalie.
And we get four pieces of cutesy sexual slang: ta-tas, ni-nis, miss pretty, and whoopie spot. Only the first of these (tatas / ta-tas / ta tas ‘breasts, boobs’) is at all common, and it’s very common indeed; there’s even a Save the Ta-Tas Foundation, providing breast cancer awareness products.
The expression appears to be derived from tittie, by babytalk reduplication.
So with ninis / ni-nis / ni nis ‘nipples’. (Nini is also used for a silicone nipple: a pacifier, dummy, binky, or soother.)
[Irrelevant ambiguity, induced by the Mexican Spanish slang ninis. Spelled solid, hyphenated, or separated:
Los ninis are young people (aged 12-29) that “ni trabaja, ni estudia” (neither work nor study). (link)
Even for those who can get through the over-burdened educational system, there are few economic or social opportunities. It is no wonder that “ni-nis” — youths with “ni trabajo, ni escuela” … neither work nor school … are a growing segment of the Mexican population. (link)
Mexican media talk about a new category known as los ni nis or "neither nors" — young people who neither work nor study. (link)]
Miss pretty turns out to be a truncation of the alliterative miss pretty pussy, as in:
I love how in my scene with … I tell him to kiss miss pretty pussy. Haha he gave me great birthday sex I’d have to say. (link)
lick miss pretty pussy (link)
And then whoopie spot, another piece of female genital slang, referring to the vulva or vagina, or in this case maybe the clitoris — in any case, the place for making sexual whoopie (or whoopee). (There might be an allusion to the fabled G-spot in there.) No relevant ghits, so this looks like an imaginative innovation.