http://www.mangago.me/read-manga/links/ (one of the couples but his story is just so great!!!)
http://www.mangago.me/read-manga/ame_to_kiss/
I have some others but I couldn't find them, sorry ^^'
And bonus prize: http://www.mangago.me/read-manga/saezuru_tori_wa_habatakanai/ (in a way it works, okay? and even if you don't agree the manga is great)
i think its called sad toy in a box
Yaoi mangas where the relationship is not clear, like the uke doesn't know where he stands in seme's life so it makes him insecure ?