The demon Lord and you have been in a fake relationship for quite some time,as you need his help to keep away the people that keeps on pursuing you.

yes,he brings back random girls sometimes but you didn't really care,no.You just needed his help and once it was all finished,you can just leave him,right?

clearly it's not the case now.

"mc,why are you leaving now? don't you know that it's rude to leave your lover alone? gosh,if only i could lock you in here forever." he said,smiling