Mariah Carey's ex-boyfriend is extremely "heartbroken" over the singer's shot gun wedding to actor Nick Cannon.

Carey dated Mark Sudack for four years and broke up earlier this year. After that long, you would think Mark knows Mariah is a heart breaker!

“Everyone is scared to call him because no one knows what to say,” a friend close to Sudack says. “He never thought she would go off and marry someone else. He’s heartbroken and shocked.”

Nick and Mariah are, of course, on their whirlwind series of wedding parties and honeymoons including beach parties and amusement park trips.

Poor Mark is sitting in his apartment crying.

I'm not sure if I approve of Cannon as Mariah's groom... I guess we'll have to wait and see if they're in it for the long haul or not.