Surprising my husband with a sudden lock-up, what do you recommend?

My husband has shown interest in being locked up before. Up until now, we never really kept him that way for more than a week. He’s been traveling for business this past month, and every time we talk he mentions how eager he is to return home so we can have sex. I’m thinking of surprising him. When he returns, I want him to believe we are going to have sex, but then lock him up instead. His expression will be priceless, especially since he has always said he wanted to try it. I am looking for ideas on how to handle this. We currently have ties attached to the four posts of the bed, and while he likes being locked up, we usually end up having sex afterward, so tying him down won’t really surprise him. I’m trying to decide between having sex first and then quickly locking him up while saying I hope you enjoyed your last time, or perhaps giving a ruined orgasm first. Another option is just bringing him right to the edge and walking away until I can actually put on his cb6000. Any suggestions? I want the most frustrating approach for him. Thanks