Here’s some~
http://www.mangago.me/home/mangalist/921591/
http://www.mangago.me/home/mangalist/714069/?filter=&page=4 these r my fluffy recs and most (if not all) have semes that are sweethearts bc that’s my type lmao!!
It really doesn't have to be shounen ai there are many yaoi where seme is not a jerk like these:
http://www.mangago.me/read-manga/hitotsu_shikanai_mono/
http://www.mangago.me/read-manga/itonaga_kun_no_koi_no_ito/
http://www.mangago.me/read-manga/koi_ga_ochitara/
http://www.mangago.me/read-manga/sugar_dog_life/
http://www.mangago.me/read-manga/konna_nichijou/
http://www.mangago.me/read-manga/rumspringa_no_joukei/
http://www.mangago.me/read-manga/chijou_100_meter_de_aimashou/
http://www.mangago.me/read-manga/asatte_ni_kiss/
http://www.mangago.me/read-manga/hana_to_usagi/
http://www.mangago.me/read-manga/kokoro_kanda_neko/
http://www.mangago.me/read-manga/kimi_to_no_dogfight/
A really good one is Tale of the Yellow Dragon both the Seme and the Uke have a pretty great relationship and it has an interesting storyline to go with it (although it can be a bit confusing sometimes). Another good thing about it is that it’s already completed so you can binge read it without having to wait for more chapters.

Can someone recommend me a good Yaoi where the Seme is not a f*cking jerk axsjdsdkj (๑•ㅂ•)و✧