https://www.mangago.zone/read-manga/beast_knights/ (poly relationship, there are some threesome scenes but don't remember the specific chapter it happens in)
https://www.mangago.zone/read-manga/goukaku_no_tame_no_yasashii_sankaku_kankei_nyuumon/ (poly relationship, don’t remember if there is any threesome scene though)
https://www.mangago.zone/read-manga/there_s_weird_voices_coming_from_the_room_next_door/ (poly relationship, don’t remember if there is any threesome scene though)
https://www.mangago.zone/read-manga/my_younger_senpai/ (chapter 26; age gap & mild self-cest)
https://www.mangago.zone/read-manga/watashi_no_shumi_tte_hen_desu_ka/ (chapters 7&8)
https://www.mangago.zone/read-manga/asumi_chan_is_interested_in_lesbian_brothels/ (chapters 8&25)
https://www.mangago.zone/read-manga/tada_de_wa_dakaremasen/ (chapters 16, 24, 38, 54)
https://www.mangago.zone/read-manga/yurika_to_kawakanai_shiitsu_midare_yuri/ (one-shot)
give me threesome yuri thanks