He likes cheese. He hates Father's Day. It's sort of a wash on the punishment/reward front, but as long as Dick is going, Bruce isn't going to complain. He is going to go right back to one of the workstations, hold his head in his hands and wait for drugs to kick in.

And time precisely how long it takes, so there's no risk of gaps, and minimal overlap.

Also because it means counting seconds and watching the passage of time, rather than going to eavesdrop.