A wasted orgasm is when you jack off and come but don't feel an orgasm, due to trying to prolong the pre-orgasm pleasure for too long. Usually leaving the victim with a sense of failure and frustration.
Frat Bro 1: Dude last night I was jacking off and I came and felt nothing, totally fucked up my night.
Frat Bro 2: Oh yeah dude I think that's called a wasted orgasm, I get those all the time when I think about my grandma.
Frat Bro 1: ....What the fuck dude?
Frat Bro 2: Wait what....?