go search here:
http://www.mangaupdates.com/series.html?page=1&category=threesome
http://www.mangago.zone/read-manga/kimochi_no_yukue_meiji_kanako/
http://www.mangaupdates.com/series.html?id=4570
http://www.mangaupdates.com/series.html?id=6248
http://www.mangaupdates.com/series.html?id=4446
http://www.mangaupdates.com/series.html?id=72696
http://www.mangaupdates.com/series.html?id=47803
Threesome yaois:
-6mm no Taboo (ch.4)
Koisuru Omocha (Ch.5)
Goshujinsama to wanko (ch.7)
Knock 3 times
Hard Core Heart
Pet Keiyaku
Mob for Jack
Gravitation DJ
Joker Trap
Glow Vampire
Junk! Boys
Katayoku no Sokubaku
Prisoner (Kaen)
A Sex Therapist (last ch.)
Viewfinder (ch.: 35.3)
Hot Triangle
Kunshu no Ai wa Yoru ni Hana Saku (ch.6)
Mukizu ja Irarenee
Koi no Kawaki
Groupie
Himitsu no kemonotachi
Kimagure love cupid
Bachi Bachi
Partners
Sadistic Boy
Tsukiyono Fushigi (Ch.3)
Tsumibito no Kiss (Ch.3)
I sortof lost the list for yaoi threesome mangas. Can anyone tell me good yaoi threesome ? Thanks