For me, Haemi is a bit extreme for him. They don't balance out. When they are together, it's always seemed to go her way, while he just follow along without much choice. Don't know, just like equal relationship if possible.
First of all, he doesnt seem to have any romantic feelings for Haemi so I don't really think the author will even go in that direction. I mean, if Haemi likes him thats fine but it doesnt mean he will like her back. At least it doesnt seem like the author wants it to go in that direction. Besides he always wished he treated his wife better, so I hope if he gets a chance to be with her, that he will make her happy and that they will have a long healthy life ahead of them.
I actually ship him with his previous life's wife, Yeonhee than that Haemi girl. Idk i just dont like Haemi that much idek why...