Fck! I totally know what you're talking about but it got lost in the sea of mangas that I've saved in my list... I'll try my best to find it
I feel you. I read this mangan before XD
It does sound like I'm your cute copycat. But it is not a oneshot.
http://www.mangago.zone/read-manga/i_m_your_cute_copycat/
i have also read this one
http://www.mangago.zone/read-manga/5_seconds/nbt/c004/pg-1/ found it
I litterally don't even remember that much details so bare with me.. It was oneshot book I believe and there was this one chapter where this seme would copy an outfit from the uke starting off with like shoes, or a shirt then it would lead to the whole outfit being snatched and by the end the use confronts him? I'm it sure if remembered it right but help please
(๑•ㅂ•)و✧