Erm..

Can two people be together only for the purpose of hurting or pursuing some sort of personal vendetta against someone else?

Usually an ex-girlfriend or ex-boyfriend, or an ex-wannabe-boyfriend or girlfriend? An ex-best-friend? An enemy?

I've seen celebs doing it.

Stavros used to date Paris, and now he's dating Lohan only to get back at her. - Because he knows that Paris hates Lohan, and Lohan knows that too. So, logically, they are together, Stavros and Lohan; and Paris is at least feeling bothered.

I can't stand those people.

Please, STOP! You make me feel nauseated.

(This isn't aimed at my baby. I utterly love you. Forever. It's just social criticism. :P)