ничтоже сумняся

ничтоже сумняся (сумняшеся)

уст., ирон.

not giving it a second thought; without any hesitation (a moment's thought); suspecting nothing; nothing wavering; with never a blush

Свёкра, Бориса Тимофеича, ничтоже сумняся, схоронили по закону христианскому. Дивным делом никому и невдомёк ничего стало: умер Борис Тимофеич, да и умер, поевши грибков, как многие, поевши их, умирают. (Н. Лесков, Леди Макбет Мценского уезда) — Those who buried her father-in-law, Boris Timofeyich, suspected nothing. There was nothing unusual about the matter, and nobody gave it a second thought. Boris Timofeyevich had died after eating salted mushrooms, as many others who had eaten them had died before him.