I love both to watch a partner masturbate and to masturbate in front of my partner. Its fun and a great way to see what they like to do themselves to get off.
Mutual masturbation is one of my favorite kinds of sex! I love watching my partners masturbate, and I love them to watch me while I do. Sometimes we help, sometimes we just cuddle, sometimes we watch from afar.
Of course I do. When you share a bed long enough, sometimes you have to take care of things. We don't even make it a big deal... That may be a little weird. If one of us "helps" its just kissing, because I think if they help more than that you are having sex (at least in my same-sex relationship).