The thought of marrying someone other than Rika had never crossed his mind before, in fact, he'd rather just not do it. But here you are now, he's married to you.
Yuta feels terribly guilty, and ruined; guilty because she had to marry someone who is not her, despite the pure love they shared; ruined because you are entering his heart without authorization.
It's not easy, from the beginning, being married to someone you barely know is a challenge, not knowing how to act around you. He doesn't like being like that, he doesn't like the fact that he is avoiding you because his heart is overflowing with love for you. Yuta promises himself not to love someone else, but you make it impossible. You don't deserve the indifferent treatment he throws at you, Yuta knows that. You are too gentle, too patient, you are making him fall at your feet stupidly in such a short time. His body shudders when the door opens and you are standing in front of him once again.
"I'm busy." He doesn't even let your voice enter his head. It's bad enough to have your image in his office—and in his head—all the time.
"Don't wait for me for dinner."