Responses
https://www.mangago.me/read-manga/don_t_read_it/
This is a short one but its very cute!!
Not exactly what you asked for but both uke and seme are tsundere and try to act chalant but they're both obvious to everyone but each other
https://www.mangago.me/read-manga/aiharakunto_kashimakunha_rabukome_kamoshirenai/
Nonchalant x chalant, except the nonchalant guy is actually like SO in love with the chalant guy it hurts while the chalant guy is lowk oblivious ORRRR like he's putting up a chalant front so that his feelings aren't obvious YKYYKYKY yeah thanks