The act of sleeping with or dating someone for with no intention of ever having a serious relationship with them and then dumping them after 3 months/90 days as to move on or to keep from hurting the victim of the affair. Often, both parties know that they are not suitable for each other.
Smart, attractive, jaded, and/or hypersexual females are often the culprits of ninety night-stands. Rich men, players, married and/or hot men are also frequent culprits. These people are not necessarily players, but they are opportunists.
Young, needy, cute, plain and/or naive women as well as women with low self esteem who are good in bed are frequent victims. Unemployed, hot, lower class, stupid and/or neanderthalic men who are good in bed are frequent victims.
Jim: I've been dating this smokin' hot music executive for a few weeks now. She is so perfect. I want her to be my sugar mama.
Tom: You dumbass. You fold shirts at Banana Republic for a living and you don't even have your GED. You're her ninety night-stand.
Angela: (sobbing) I can't believe that Dr. Spencer broke up with me. He was so great and so good in bed.
Psychiatrist: You dumb bitch. He's married to a total MILF. You're not even that cute. It was a ninety night-stand, not a relationship. He just wanted to try stuff his wife wouldn't do and throw you to the curb.
Angela: But he said he loved me after we slept together.
Psychiatrist: He probably meant that he loved that you'll do all the freaky shit his wife wouldn't do.