Recommend

http://www.mangago.me/read-manga/honto_yajuu/
This one is really funny and the characters are great. They don't always act like that, but I guess sometimes when they arguing they can remind you of a married couple, it's all around good feels

I already read that

Ah welp what can you do, I'll try searching for something else but idk. For now you can try:
http://www.mangago.me/read-manga/how_much_i_like_you/
But I still haven't read the whole thing so I can't tell you what it's like. But for what I've read it's pretty good and cute. The 2 guys are living together but they aren't married.
So maybe give it a try. ٩(๑❛ᴗ❛๑)۶

Thank you

Okay, so, I read "how much I love you" and I think it's alright, not the best but it has it's moments. But I found so mangas:
http://www.mangago.me/read-manga/motoyan_papa_to_hitsuji_sensei/
-this one is really cute and it's one of my favorites. I'm pretty sure they aren't married but they kinda act like that.
http://www.mangago.me/read-manga/oh_my_assistant/
- this one is great. It's not really what you asked for but it's cute
http://www.mangago.me/read-manga/life_senjou_no_bokura/
- this one is really good. But idk if they get married
http://www.mangago.me/read-manga/can_t_take_my_eyes_off_you/?av=2
-this one is also cute but I forget how it ends.

That's all I got. And most of them aren't exactly what you asked for but I tried

Omg, thank you so much!

You are very welcome