Why not legs and arms?
I've trained with my wife before, and it was just fine. I let her do her thing, and she let me do mine. I don't think critiquing each other's form would go over very well with either of us, LOL.
well...my wife competes in figure/bodybuilding and will be doing womens physique at the North Americans this fall. I train VERY heavy with legs and my goals are much different than hers when it comes to legs.
Arms...she is gentically gifted and very rarely even trains them other than a few shaping movements. I, on the other hand, want the biggest arm I can get...
Other than that we train everything together and have fantastic workouts.
back workout looks like this for us typical:
chins-weighted for me
bent over rows- wife loads a seperate bar for her.
seated rows
1 arm dumbell rows.
pull downs and finish off with hypers.
she pushes me harder and doesnt BS. We both wear our Ipods during training and mostly use hand gestures to know what we are doing next....
We finish up with cardio and then off to eat...perfect system for us.