A pronouncement of the termination of a relationship by either one of the two parties involved in said relationship or an outside, objective party.
You: "Things were going so well. I called her twice a day, e-mailed and IM'ed her every five minutes, and gave up all my friends to hang out with her just to show her how much I cared. I honestly don't know what happened."
This phrase is often used while playing video games against one other opponent. Typically the game that is at hand is a sports game, either on PS2, Xbox 360, or PS3. Most often its a basketball game. The phrase will be used when one player has been beaten mercifully 4-5 times in a row. The phrase will be used at the beginning, middle or at any time during the game, when one opponent feels his efforts are hopeless.
Send one over, as in a beer or some other kind of alcoholic beverage. However, it is said when the person is already HIGHLY intoxicated so that their partner mistakes them to be breaking up with them. Send one over is slurred into one big pile of ex-mess.