bump heads with

But congressional investigators must take pains not to bump heads with the FBI’s inquiry.

We love watching April bump heads with the father of her calf, like we loved watching young National Zoo panda Bei Bei snooze on top of her mom, like we love watching bears catching salmon in an Alaska national park.

He is on the extreme side of the immigration debate and will likely bump heads with other candidates on the stage who are more moderate.

The first two or three times you bump heads with the passenger sitting opposite, you can smile and apologize with some grace, but after a while your hat will not stay in place and your head becomes sensitive, and finally, you discover that the passenger is the most disagreeable person you ever saw, and that the man sitting beside you is inconsiderate and selfish, and really occupying two thirds of the seat.