Hello, i'm looking for a manga that i read a long time ago and i'm not sure if i finished.

It's about a rich girl who runs away with his servant after his parents told her about an arranged marriage, and they start living in an apartment like a couple.

It was probably a hentai, because there were sex scenes and stuff.

I remember that the guy she's supposed to marry is a manipulative guy, who already has sex with two/three woman, and sends someone to spy on them by having her be their neighbor.

Ojou-sama wa Nigedashita

That was it, Thank you.