Is it possible to be having a life that is happy but too emotionally and socially fulfilling to have sex? For a lot of couples, the answer is a resounding yes.

For some people this seems like a riddle. But for others it’s obvious.

Having sex that is more than just a quickie takes time. And for many of us, time is even more valuable and scarce than money.

The answer is to make dates for sex. But no one I know feels good about doing that. It’s as if you’re admitting to some kind of flaw or failure. We tend to believe that sex should “just happen.” If it doesn’t happen spontaneously, too many people just give up.

I’ve been preaching about the need for mature couples to arrange actual dates for having sex for more than 30 years. And I think we need to do make such arrangements more than ever today.

We all have jobs, and many of us with younger children have lives which are run by their schedules. All of us have single and couple friends who want to hang out and see us. And each of us is competing with our own cell phones and our partner’s cell phones and our children’s cell phones for a moment to breathe.

Sad as it seems, there are some happy adventures and social get-togethers each of us might need to pass up in order to schedule ourselves for sex.

Like they used to say about money: “Pay yourself first.” Financial advisors were saying that we have to put aside some money as an investment for the future before we dole out the rest of our hard-earned cash to other purchases, obligatory or optional.

We’ve now gotten to a place where we have to do the same thing with putting sex into our calendars. If you don’t, chances are your sex life will wither and perhaps die altogether.

The trouble with having sex infrequently is that it becomes more risky, emotionally. If you have a lot of sex, some of it can be more ordinary, some of it can go not quite perfectly, and then some of it will be really pleasurable and great.

If you have sex infrequently and that rare sexual experience is disappointing, you’re more likely to avoid having sex again.

When my children were small, I sometimes would turn down getting together with couple friends on a weekend night so that my husband and I could have some alone time together. One friend felt rejected and wanted to know why I sometimes didn’t want to see her.

I told her the truth. My husband and I couldn’t fit in the time to talk, have dinner, and get home at 11 p.m., and then still have time to fit in pleasurable sex and still be rested enough to get up the next morning. (I write about this in my book Sex Talk.)

She thought I was insane. But I still think my way of juggling sex and the rest of life was right, and I would make the same decision again.

If you are an otherwise happy couple whose social and family life is flourishing but whose sex life is nonexistent, start penciling in time for sex.

It’s an investment in your lifelong strength and happiness as a couple.