As long as he wants to I would say, there are so many things a man can use to achieve orgasm and still squirt his cum either in his hand or on the floor. There is of course viagra or similar medications that help get an erection. I am 74 and continue to mastubare, maybe not as often as I once did but a good cum is A GOOD CUM.
There are also a number of vibrators out there help if one needs help. I have several sex toys that give me pleasure. I also have a pump that allows me to "pump up my Cock and with the aid of a cock ring I can keep a hard on for some time. Writing and readingf sex stories also helps me to get and maintane hard on and I kind of hope they don't quit making KY which is an elixer for my dick.
There is also the adult sex stores where I can always find some one to stroke my dick for mt. I had a feloww the other day who liked to play with me butt cheeks with his hands inside of my pants I really like that then I felt qhat I thought was a finger, but it was his hard cockand as soon as he was inside he came and I came in my pantes. So as you can see I can still creat a mess. Would luve to hear from you with a PM. By Luv.