In the Dream SMP (meaning Survival MultiPlayer), there was a joke created that standing on a
crafting table meant to have sex, or more specifically, to give/receive a blowjob. (Search 'crafting table' for more info) Skeppy, one of the players on the Dream SMP, took that joke and extended it to include furnaces, saying that standing on a furnace was "worse." Only he knows what he truly meant, but the fandom took that to mean sex. For example, versions of
the furnace jokes, instead of just receiving a blow job, the people "standing on a furnace" for each other
do what you do with furnaces; you put your meat in one ;). There have also been jokes regarding enchanting tables, which is a step after that.
"George~, would you ever stand on a
crafting table for me?"
George looked up at
Dream's smiling face. He sighed and quietly responded,
"I would stand on a furnace for you."
Dream's smile dropped as he realized what that would entail. He quietly approached the smaller man.
"Would you now?" Dream asked, just as quietly. There's no way he could be serious. Right?
George stared back, unblinking, and then broke the eye contact. He
wordlessly reached out and grabbed Dream's hand, led him to the kitchen, mined one of the stacks of furnaces down so that there was just one, and then climbed on top of it.
George smirked and stood up for a second before crouching so that their faces were level. George pulled Dream in for a kiss. After the two men severed the contact, Dream blushed profusely, climbed onto
the furnace, and began to kiss his again with
more fire and passion than before. One thing led to another, and Dream's dick ended up inside of George. Multiple times. And they made love in the kitchen for hours. George couldn't walk or remember his name afterwards.