o.p.p., n. — Green’s Dictionary of Slang

o.p.p. n.

[abbr.]

(US black/campus)

other people’s property/pussy, usu. their wife, husband or partner, esp. in the context of their being ‘off limits’ to new sexual approaches; thus an illicit sexual liaison [pussy n. (1)].

1992		Eble Campus Sl. Apr. 7: opp – someone else’s boyfriend or girlfriend.
1997		C. Newland Scholar 269: Tara, who was gazing at Garvey and Claire jealously, even though she had a man. Cory was sure some OPP had been going on.
1999		Hip-Hop Connection Apr. 29: I’m talking about [...] being down with OPP.
2002		‘Touré’ Portable Promised Land (ms.) 157: We Words (My Favorite Things) [...] TLC. TCB. CPT. PHD. OPP. BMOC. HNIC.

In phrases

you down with o.p.p.? [down adv.² (1)]

(US black teen) do you respect other people’s property?

1991		Naughty by Nature ‘O.P.P.’ 🎵 You down with OPP (Yeah you know me) / Who’s down with OPP (Every last homie) / You down with OPP (Yeah you know me) / Who’s down with OPP (All the homies).
2012		‘Dutch’ ? (Pronounced Que) [ebook] OPP really stood for Oval Park Posse, a crew in East Orange, New Jersey. At parties, they used to yell, ‘You down wit’ OPP?!’ Everyone would respond, ‘Yeah you know me!’.