I met my partner at a dinner party ooo about 18 years ago. She was going through her divorce and I was going through mine. Needless to say, we had lots of commonality back then. We are best friends to a point its like we are sisters more than anything else. for simplicity sake, we just go along with the term partners.

She's the artsy type and me more of an engineer type. But I can also see things in artsy way too, so I guess I'm borderline bipolar?? Anyway, she keeps me well grounded in a way I need to be. I keep her grounded in a way she needs to be. And I share my house with her. After what we both went through with our respective divorce, we have zero interest in getting married again or for that matter dating again.

I need my best friend to keep the dark cloud away from my head. She has a wonderful way of making me smile. And I bring bit of stability to our lives and an ear for her to talk. We are complementary in areas where we need some balance, not being so far out in the left field, and similar in areas to have connection between the two of us. Her dogs and my cats are our pets as an example.

for nearly twenty years of knowing my partner and living under the same roof for the last 5 years or so, we have gotten along just wonderfully peachy. and that't the truth. Yup she's my family.

The short answer I guess is complementary and similar. Complementary in a sense to fill in the deficit not to mean opposite.