1. 'Party rock' is a place. Like a cliff where people go to drink, ****, and ****. Her boyfriend is going to fall off it one day because he's drunk and not making wise decisions. She's part gypsy so she sees this coming, and she told him about it, but that's where the not making wise decisions part comes in.
2. It's a rock, nicknamed the party rock, and someone is going to hit her boyfriend on the head with it... and he dies. The first one makes more sense, I think.