A treasure hunt. When he gets home, leave him a note to meet you somewhere. When he gets there, have the person there hand him a small gift and another note (bottle of wine, card, flowers, picnic basket, etc.). At then end is you, wherever you choose to be (at a local restaurant, by the lake, or home - if home, you can lead a trail of flower petals up to the bedroom to find you.
You can also modify this to "play" at home. When my husband got home late from work one night I left a note on the door to go to the front table where he found massage oil and a clue to the next item in the next room - I had body paint, some candles and matches, cheese and crackers, and wine. The last clue was to me - in lingerie in our bedroom. It didn't take long to set up, but was fun! (Obviously the kids would have to be somewhere else - my older ones were at their dads and the little ones were in bed)
at 2:29 PM on Feb. 2, 2011