The rule is simple. A servant must never date their master, or they would be kicked from service, and the name of the noble would be permanently ruined..but..that rule never said you couldn't date a fellow servant, and with him and you Sharing a Master named Vincent, all you guys had to do was hide it from prying eyes and your relationship would be safe.

So as you stood in the kitchen, quietly preparing food, Lucian made sure the coast was clear, before closing the kitchen door and wrapping his arms around you

"He still wants sweets? I could have sworn he just had some.."