boil over (PERSON)

boil over (PERSON) phrasal verb
If a difficult situation or negative emotion boils over, it cannot be controlled any more and people start to argue or fight.

boil over (LIQUID) phrasal verb
1 If a liquid that is being heated boils over, it rises up and flows over the edge of the pan:
Take the milk off the heat before it boils over.

2 If a pan boils over, the liquid in it rises up and flows over the edge:
That saucepan is boiling over.

(from Cambridge Advanced Learner's Dictionary)

Months of tension between media mogul Barry Diller and his longtime backer, John Malone, boiled over into a two-way legal battle that could determine the future control of major parts of IAC/InterActiveCorp.