bone of contention

So this issue became a bone of contention between the two.

This seemed to be the big bone of contention between the two.

The main bone of contention is not drugs, but direction.

They've al- ways been a bone of contention in the family.

"Since this seems to be a bone of contention between us."

A new black market has become a bone of contention for the residents and the government, however.

But it was far from clear today that these issues were the real bone of contention.

At this point, I want to focus, in particular, on the bone of contention.

We know that it had been a bone of contention for years.

How could it have happened that they had become a bone of contention between us?