Fact #1: Men''s attraction to women is almost solely based on sex appeal

Fact #2: Women's sex appeal is impacted by age much more than a man's is

Conclusion: There will always come a point when your man's SMV becomes drastically greater than yours and he can upgrade to a younger model.

Men want young women, older women cannot compete. I say this as a woman. Investing in a LTR won't bring about the fairytale life that most women want. His love for you will become like the love for a friend or a mother or a pet. If he's high quality/if you find him attarctive he will eventually surpass you and find hmself someone younger, the only me that will remain monogamous forever are the ones that aren't high quality and aren't worth your time to begin with (discounting for those religious and easily swayed by social pressures) it's a double edged sword.

Get yourself a man if his resources are valuable to you or if you might enjoy him in the mean time, but know once you grow old he won't love you anymore, the moment you grow older than 16 he will find younger women more attractive than you (look at "teen" being the most popular porn category). Get a man as a short term source of money, fun and children, but know he won't truly love you and you'll need find fun and fulfillment elsewhere once you're old and he's fucking his secretary.