Well, it depends... if the wife WANTS him to help with that, great. If not.... gross.
I'm currently getting my butt absolutely kicked by a horse trainer. I've told him I want him to, and my mom was a little shocked when I was going to rest during one of my lessons and he yelled at me not to be a wimp and keep going. However, we had discussed it and he knew that was what I wanted him to do, and I told my mom not to worry - I desperately want to be back in shape, and I appreciate being worked that hard! (He also takes things into account like he could tell I was stiff/sore from some work so had me do other things for two days until I was feeling better, rather than ragging on me for not being able to do as well as I had before getting sore. A good personal trainer is going to be the same way.)