Surely with the genetic engineering capabilities science has they can invent a type suckling device..like a piglet with human mammary glands and milk. Easy to transport and install. Allowing the human females nipple to be used exclusively for sexual purposes.
You and I should pool our venture capitol and open the Universe's 1st milking bar, where patrons can squeeze fresh milk from the mammaries of any ethnicity woman of their choice.
It would only be fair then to expect the man can achieve and maintain a fully hard erection that doesn't require 6 bathroom trips. Aging is a bitch but so is trying to shove a marshmallow in a keyhole