Jon Bon Jovi was reluctantly coerced by a wedding singer, at a wedding he was attending, to join in because they played a Bon Jovi song. He was clearly not happy and allegedly asked the chick not to try to get him to sing.
There are some things that make me think it's all made up. He couldn't be seated any closer to the band. Sure he looked pissed at the beginning but he's an entertainer, it could be an act. She had the second mic ready.
He gave in pretty quickly to her pressure too.