[Xp] switch and pair programming

The working day starts with a stand-up meeting.
One of the key points is define the daily plan: who is working on what.

Sometimes i hear: " today i don't want to switch pair, i want to continue to work with the same coworker "

I think it's exactly the time when the switch is necessary.
I think the pair is working in a comfortable area; he know that his solution is not the best, but it works for the current task.
Probably he neither want to describe his problem nor to share his solution.

The bells are ringing!