do social / adventure / date activities together a few times a month
spend some time at the gym together each week and/or exercise socially (bike, climb, etc)
spend the night together 1-3 nights a week
have intercourse less often than other orgasmic pursuits
get tied up and engage in other D/s and kinky activities occasionally
... or at least some of the above. Obviously I don't expect someone to exactly match all of that; it's just the middle of the ballpark that I'm aiming for.