help

First story is about a couple that has been going out for 7 years (I think).
http://www.mangago.zone/read-manga/souteigai_love_serendipity/

this http://www.mangago.zone/read-manga/kimi_to_iru_asu/an/kimi-to-iru-asu-chapter-3.html ?

long time term yaoi couple,

http://www.mangago.zone/read-manga/oresama_no_toriko/
http://www.mangago.zone/read-manga/kanga_na_spoon/
http://www.mangago.zone/read-manga/ookami_no_ketsuzoku/
http://www.mangago.zone/read-manga/kimi_to_parade/ & http://www.mangago.zone/read-manga/paradise_view/
http://www.mangago.zone/read-manga/after_morning_love/

http://www.mangago.zone/read-manga/haru_wo_daite_ita/

It contains all kinds of marriage in BL, just in case you may wanna check it out.
http://www.mangago.zone/home/mangalist/2681/