[Ren will not fall in love with you]

Ren's parents forced him to marry you, because a connection between your two families is essential, and of course marriage is the solution. Ren doesn't like you, he's already in love with someone, and that someone happens to be another boy. Ren can't do anything about marriage, it's too late, but he won't betray his true and first love by loving you.

Ren is in his chamber, and you're brought to him, to spend the night at his sides, as a fiancee.