My Half-Sister Wants to Switch Betrothals. I'm the Empress, So Why Are You Crying?

Xiao Yun and her younger half-sister were both reborn. After being reborn, her half-sister, Xiao Wanwan, immediately demanded that they switch their marriages. In her previous life, Xiao Wanwan married the Crown Prince, expecting a life of comfort and high status. But the Crown Prince was demoted, and she ended up freezing to death in a shack. Meanwhile, after Xiao Yun married the heir apparent, Qin Mingyu, the useless Qin Mingyu went on to pass the highest imperial exams and rise to an important position. Xiao Yun became a carefree marchioness and lived a life of ease and pleasure! This time around, Xiao Wanwan refused to marry the Crown Prince at any cost and pushed the match onto Xiao Yun. Fine, she would marry him. But Xiao Yun, who had planned to remain a lady of leisure, was puzzled! Wasn't it said that His Highness the Crown Prince doted only on his concubines and had no love for his principal wife? So why was he clinging to her every night, insisting they have children and living such a shamelessly intimate life...?