See, I have had 15 partners..... he's had 40+ and it's never been an issue until the past year or 2, don't know why, :/
I am female and all my partners, including my current one, masturbates. Sometimes he has been sat in the other room, sometimes when he's been away, sometimes during our sex we do it in front of each other for for a different kind of foreplay as we like watching each other doing it. I'm only 23 so not miles older than you but maybe after you have a few more sexual partners you will learn each of thier prefences, and you may find some else who thinks masturbating is a waste of time.
it may just be due to the fact of my relationship issues and how it has destroyed some of my relationships. in past ones, my partner would eventually just get bored and constantly maturbate and for almost a year we did not have sex at all. he would just do it. so it could just be from my past experiences. it may also have to do with the fact that my partner has had MANY, and when i mean many i mean 40+ at 23 years old. having some emotional issues personally could also just effect it. :/ we have had issues of me having an orgasm before him, so it could be that as well.. i thank you so much for all of your help, and it truly could be me just not doing it enough! haha thank you so much for your help hun :) it's nice to have an outsiders perspective