The male contestant on the 13th season of ABC's "The Bachelor". Once deemed a nice guy, he was the first divorced single parent to become the Bachelor. Rose to prominence as the runner-up on the 4th Season of "The Bachelorette" in which contestant Deanna Pappas allowed him to get on his knee to propose before rejecting him. Many people felt sorry for Jason and petitioned him to be the next Bachelor. He's considered a man with a "nice guy" image who became very popular and increased ABC's ratings for the show. However, the controversial events of his season have turned him arguably into one of the most hated contestants ever. He proposes to Melissa Rycroft at the finale, announces in press releases how happily engaged he is shortly thereafter, and then two months later dumps her on national TV for the runner-up Molly Malaney, who eagerly takes him back. The plot was apparently scripted and uncovered by gossip blogger Reality Steve.
"Jason Mesnick, you're such a Bastard" - quote by Melissa Rycroft at the firstAfter the Final Rose ceremony.
When you are dumped by a significant other, only to find out that they are going to ask another person out right they dump you. Bonus points if it is a friend or their ex.
Oh damn, did you hear about Mandy and John? He dumped her to start dating his ex again. She got mesnicked.
Or
You know when I stopped dating Bob for Julio? Well, I may have to mesnick Julio, because Bob's looking hot right now.
He mesnicked all the viewers of the show when he pretended to be 'Mr. Nice Guy' and then dumped his girlfriend for another woman. (reference from "The Bachelor" Jason Mesnick)