[NSFW] What is something kinky I can do for my boyfriend?

Me and my boyfriend have been together for awhile. He can be a smart ass sometimes. We have a bet going now. If I surprise him with something kinky then he pays the bills for the next month and cleans the house by himself. I want to surprise him with something really good that he would never expect to show him how much I love him and apperate all he does for me and my family. I am stumped and need some help please!