reminds me of http://www.mangago.me/read-manga/mimurake_no_musuko/
i'll just copy my review from my list lol
seme & uke's older bro has physical relationship at vol. 1
physical: semexuke's is slow-paced.
emotional pacing: uke's very slow uptake in love is nice. seme has a secret crush on the younger bro.
length: 3 vols, has explicit smutty chaps
Thank you very mats takame senpai （/TДT)/ as usual, you help me in every yaoi hunting thank you!
Maybe you will like this http://www.mangago.me/read-manga/itoshii_hito/
(๑•ㅂ•)و✧
Something like uke is so much in love with the seme but then the seme likes another guy or girl and they have physical relationship but at the end, uke and seme ended up together. Oh and a scene where uke finds out a seme having sex and have his heart broken humaygahd i'm craving for this.