I assume you've already read the Junjou Romantica series and sekaiichi hatsukoi. Going beyond the most obvious:
the Black cat series
http://www.mangago.zone/read-manga/kuroneko_kareshi_no_asobikata/
Lot's of smut and a very lovely relationship (even if it doesn't seem so in the begging. Just trust me) It has several sequels.
http://www.mangago.zone/read-manga/punch_up/
Metalworker x architect. LOTS of love and sex. Must have read this at least 5 times now
http://www.mangago.zone/read-manga/elektel_delusion/
Sweet love story, lots of sex and a lot of laughs along the way
if you want more, just ask (▰˘◡˘▰)
thx so much! ╮(￣▽￣)╭
kuroneko has all that angst in the sequel tho so be warned
hey yall, im really in the mood for plenty of yaoi romance manga's with tons of sex AND LOVE. would like long mangas but will accept any! Please and thank you!(▰˘◡˘▰)