My twisted fantasy

This is a short story I just entered in a contest with the title as subject

„What on earth are you doing?!“ she asks, horrified.
Almost instantly guilt takes over me, a cold shower runs down my spine and my poor heart skips a beat. Why did she have to come in now?
It is so late and usually my sweet wife goes to bed early and sleeps like a rock…
„Diana, I...“ my stuttering doesn‘t help and her face turns from shock to disgust. There are no words to justify the situation she uncloaks me in.
Her eyes close to slits before she turns on her heels and walks out of the room.
I run after her. „Please, darling, let me explain!“
Diana stops on the way to our bedroom and turns around again. "How would you explain this to me, exactly?"
I seriously don't know the answer to that, so I decide to go with the truth...
"This damn diet you put me on is killing me - I've been fantasizing about this sandwich all day long!"

(166 words, have a great day, everyone)