http://www.mangago.zone/read-manga/reincarnated_into_demon_king_evelogia_s_world/
http://www.mangago.zone/read-manga/charming_scarface/
http://www.mangago.zone/read-manga/aggressive_sex_with_an_angelic_smile/
They're of the same author. I guess the author is fond of mini semes
Don’t know if u read these ones but here:
http://www.mangago.zone/read-manga/baby_face_monster_moto_banchou_no_ore_daga_kuso_gaki_ni_ketsu_wo_nerawerete_iru/
http://www.mangago.zone/read-manga/ore_to_aitsu_no_jikangai/
I think the second one especially fits your description quite well :)
Does anyone know any yaois where the big guy is the sub/bottom and the small guy the dom/top? Even better if the big one's a masochist lol (doesn't have to be tho)