I am looking for yaoi manga where characters are already a couple (it would be good if the...

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

This one.... To me, it's like they've been in a relationship forever... http://www.mangago.zone/read-manga/u_don_t_know_me/

Tadaima Okaeri

Pochi to Tama
http://www.mangago.zone/read-manga/pochi_to_tama/

http://www.mangago.zone/read-manga/anata_wa_boku_dake_no_hana/. Still ongoing so I haven't read it yet...(￣∇￣")
Not already a couple, but the progression of their relationship is great to see so it seems like they could've been together for a while http://www.mangago.zone/read-manga/dear_green_hitomi_no_ounowa/
SEQUEL: http://www.mangago.zone/read-manga/dear_green/

http://www.mangago.zone/read-manga/flesh_blood/. Uncle and nephew, just a warning.
http://www.mangago.zone/read-manga/love_share/
http://www.mangago.zone/read-manga/ai_no_kotodama/
http://www.mangago.zone/read-manga/cherry_ichijou_lemon/
http://www.mangago.zone/read-manga/dare_ga_omae_wo_sukida_to_itta/. Somewhat what you may want...



Some of these may fit what you want some may not... (⌒▽⌒)

http://www.mangago.zone/read-manga/souteigai_love_serendipity/
first couple

ze?

http://www.mangago.zone/read-manga/how_much_i_like_you/
http://www.mangago.zone/read-manga/kuchi_no_naka_no_shita/