when sherlock says “we have a client” in asib and john is like “what, in your bedroom?”, he is flirting so hard, this is flirting 101, his voice, his smile hidden in the words, he is like “haha, what a silly way for you to invite me into your bedroom”. sherlock could’ve said “there’s a fire” and john could’ve answered “what, in your pants?” and it would’ve been the s a m e thing