Responses
http://www.mangago.me/read-manga/natura_turaly/ (chapter 1) it's part of this anthology of BL form a girl character's perspective, but I think this is the most loce-triangle-y. Harada's chapter is also a bit love triangle-y (chapter 5)
http://www.mangago.me/read-manga/joshi_bl/
There's also these these two which aren't completed but are really good, tho it looks like he'll end up with the girl on the 1st one, too early to tell on the second
http://www.mangago.me/read-manga/that_summer_kim_hyun/
http://www.mangago.me/read-manga/10th_you_and_i_fell_in_love_with_the_same_person/
Love triangle between two boys and girl in which the boys stay together. Already read ao no flag