20s - 40+

This is most common between a young woman and an older man. The man has maturity and money, which the woman likes. The woman has a young attitude and body, which the man likes.

There are many of these relationships but few last. If you're in it for the fun and friendship, you can certainly get both of those. But remember - if at some point you are hoping for a family and home, these 20s years are supposed to be about "practice". If you instead spend these years in relationships you have little intention to continue, just what will you be practicing?