The act of having someone steal your significant other from you over the internet.
If your girlfriend dumps you, cuts ties with all her friends, and moves to another city/state/country to be with her online boyfriend, then, you have been suncrossed.
"Doode, I think I'm getting suncrossed."/i
"Yeah, I hate that @(*&!#!. S/he @(*#&$! suncrossed me."