It depends on how seriously it’s followed. My wife will often say something along the lines of “if you make dinner I’ll let you feel me up,” but it’s with the mutual understanding that she knows I’d make her dinner because she asked regardless of the reward, and I know she wouldn’t offer it if she wasn’t happy to give it - she just wants to make sure we have dinner first.

This chart’s a bit too far, though, since it’s a more long-term commitment that doesn’t factor in everyone’s feelings at the time that the rewards come due, but I could see that being circumvented in the event that a “rain check” could be called if someone’s not feeling it at that moment.