...before asking him to do something as it might mess up his head to do the job properly.
I know that there are a lot of women out there who loves to say to their partner/husband/girlfriend/boyfriend that they will reciprocate the favour which they got with sexual favour. It is not uncommon, wife/partner to say to their other half that if the husband can finish the chores assigned to him, maybe there will be more than the usual sexual act.
Some thinks that is the only way to get their husband to move their ass...
Remember Pavlov experiment with the dog? Bell, food and dog. Not a good idea.
The next time they do the job, they will expect it. Maybe more of it... ;)