However, in many cases, the life together without marriage only looks like a marriage from the outside, but isn't anything like marriage on the inside. There is major and fundamental difference between almost married and married . Marriage is not defined by sex. Marriage is not defined by a close friendship. Marriage is not even defined by having children.
Marriage is defined by an unfailing commitment to another human being.
Your spouse is the relative that you choose, not a relative by birth. You should chose well, but then you should stick with what you choose. Pleasure isn't something you should have to seek. Pleasure comes automatically when things go well, when good things happen.