John knew Sherlock noticed things. Even when engrossed in an experiment or caught up in a case, part of Sherlock was always watching John. So when he walked into the living room with Sherlock on the couch he knew Sherlock would notice him reaching for a book on the top shelf, knew his shirt would ride up just so, teasing Sherlock with a glimpse of corset and lace. He didn’t expect to pulled onto his lap quite so fast.