Anyone?

It's almost impossible to find a manga that has reversible couple.
Even more if it's treated as a natural thing. Some will build a whole drama about the seme trying to bottom as if he was going to die ... others will send you links with stories where a guy is a seme with one partner but a uke with other ... not exactly reversible couple.
Also, it depending of your taste, if you take out stuff that may not everybody cup of tea ( rape-as-love, incest, humiliation, etc) you ended up with almost nothing to read if you are looking for seke couples.
The best manga with a hot seke couple is Dark Heaven. Nowhere in the manga the uke/seme trope is inserted. They are just a couple of gay guys in love having sex as they want.
I wish so much there was a new generation of mangakas who were more open minded and modernized. The uke/seme trope is outdated and outdone to the max.

http://www.mangago.me/read-manga/dark_heaven/

http://www.mangago.me/read-manga/erotoro_r18/nmt/mi_chapter-8.1/pg-1/

i'll just drop to you the whole thing. here you can find the hot seke sex you want.
http://www.mangago.me/home/mangalist/33677/