A yaoi with an old uke maybe in their 30s/40s and young seme in thier 20s

http://www.mangago.me/read-manga/joou_to_shitateya/
http://www.mangago.me/read-manga/can_i_hold_your_hand/?sygb
And this author knows what you want:
http://www.mangago.me/read-manga/mujaki_na_wanko_to_nekokaburi/?7vGr
http://www.mangago.me/read-manga/boku_no_omawarisan/
http://www.mangago.me/read-manga/gohoubi_ha_shitsuke_no_ato/
they have more too but these are my favs

omg yesss i love niyama-sensei

http://www.mangago.me/read-manga/himono_tokodoki_shanairen_ai/
http://www.mangago.me/read-manga/kore_mo_shigoto_desu/
http://www.mangago.me/read-manga/24_jikan_ochi_nai_kiss/
http://www.mangago.me/read-manga/sv_koi_no_shinchoku_ni_tsuite/
http://www.mangago.me/read-manga/the_4th_guard/
http://www.mangago.me/read-manga/goodbye_to_destiny/
http://www.mangago.me/read-manga/kachou_fuugetsu/ first and third couple
http://www.mangago.me/read-manga/you_re_my_loveprize_in_viewfinder/
http://www.mangago.me/read-manga/love_nest_minaduki_yuu/

Thanks