I don't understand. "I decided to marry your sister because i wanted to be closer to you." That is the lousiest escuse I'd ever heard of. You should be chasing after the one you love, not his or her sister!
Maybe he knows from the start that sister loves someone else and the only way to be close to her brother is marry her, idk, maybe it's japanese way of thinking, because they are gay? But I see your point of course.
The raws: http://m.fumanhua.net/manhua/1370/217068.html
Thank you so so so much (づ ̄ ³ ̄)づ