According to the novel, Ain is actually the duke (or the "master" or somethin') But the reason why he's pretending to be the servant and hiding his real identity from Mc is because he wants revenge on the mc's father. (Ain was once a servant that was constantly harassed by mc's father)... so yeah.. pretty messy, can't remember the full details lol
yes
+ spoilers
ain is very good at acting like a servant because he WAS a servant before he became a noble and the whole point of this revenge is he wants to destroy the anatold family because michel’s dad used ain as a sex slave and passed him around so he got michel to kill him but couldn’t bring himself to do it and he tells himself he’s just keeping him around to mess with him but it’s obvious he’s grown a soft spot and he’s in denial ( ̄へ ̄)but he’s very manipulative so don’t think everything he says is true

Please tell me Ain is actually the one MC is supposed to marry, otherwise i fee like theres gonna be a lot of drama and angst.. yet, at the same time with how WELL Ain is acting (if he even IS acting) like a servant, Im just not sure D: