Lacuna, this one's for you. Complete and utter absurd crack, inspired by a fake Cosmo magazine cover.
Every so often, Sherlock got stuck on the idea of making their sex life more exciting. Sometimes, like the experiments with bondage, blindfolds, and the memorable night with the ice cubes and the warm mug of tea, the attempts were a huge success. Sometimes, like the breath play or the semi-public sex, they were fun but probably better off not repeated.
It was rare that any of the experiments were thoroughly un-enjoyable for both parties, and even if the end result wasn't a roaring success, the process leading up to the end result was always fun. So John never actively discouraged Sherlock when he said he was up for some experimentation in the bedroom.
They'd been snogging, arms and legs entangled on the sofa now for nearly an hour, and John was sporting a rather massive and uncomfortable erection. He grabbed Sherlock forcibly by the waist and hauled him up, guiding him through the kitchen towards the main-floor bedroom.
Sherlock, however, had other ideas. He had that familiar gleam in his eye, the one that meant he was up to something. He veered off into the kitchen, rummaging intently through the drawers before proudly holding up what he'd been hunting for. John blanched, leaning heavily against the doorframe.
"Christ, Sherlock... No... Just... What are you doing? Is that... an egg beater?"