How about make it an all day occasion? Pack his lunch and leave a nice little love note for him and a special container with something.. hmm.. provocative (or not) for him to think about later. This could be a token redeemable at any time by producing the item you have given him. .. In the letter, let him know why the item is with his lunch and that he can choose when to redeem it.
Send him an email or 2 or call after lunch just reminding him of the token to keep the anticipation up....
Or, give him a choice of a specific dinner (e.g. spaghetti, steak, chicken) and have activities you know he likes or doesn't like associated with them but don't tell him in advance which activity is associate with which meal, just let him know that dessert is going to be a little different. .. If you have associated a week free of laundry with meal 1, then tell him that's what he gets, if you have suggested more.. ahem.. personal activities that he will enjoy ..then so be it.. but of course all of this is in addition to the hanky panky.
