I'm not talking about sex games here (although those are important too); I'm talking about real-ass games: tossing a ball around, playing Frisbee, or having a pillow fight. Allowing yourself to really let go with the person you love is a sign that you're built to last.
They perform sweet acts of service
By no means should your partner become your slave, or act like a doormat to your every obnoxious whim. There is a big difference between doing a sweet and loving service for your partner and being a miserable wuss.
For example, my partner brings me coffee every single morning in bed. It's the most lovely part of my day and helps me start my morning off on the right foot. It isn't something he needs to do, it's something he wants to do. When you're in a solid partnership, you do things for each other that are little reminders of your adoration. It helps to keep the romance alive.
They have strong communities
Strong couples have strong friend groups and people they can depend on outside of their relationship.
"They know that even in blissfully monogamous relationships, one person cannot and should not meet all your needs," says relationship educator Kate McCombs. "Strong couples nurture healthy friendships, they practice self-care, and they recognize that it isn't appropriate or realistic to expect your partner to be your 'everything.'"