I have the reverse situation. I fly more and have tons more AA miles than my husband, but I keep his AA miles 'alive' with USO donations via AA.com.

When we travel together I usually 'spend' my AA miles for our tickets.

When I buy his tickets for money and upgrade with AA miles, he gets more AA miles in his account.

But now I'm getting a bit technical.

Fair warning: once you get in the miles game, it can change your life. Something like eating chocolate. Hard to quit.