guystander

noun /ˈgɑɪˌstæn·dər/
a person (typically male) who stands by and watches another/others struggling to do something and does not help or lend a hand, but does offer unsolicited advice on how it should be done or could better be accomplished

synonyms: expert bystander, know-it-all rubbernecker, mansplainer (see mansplaining)
As they struggled to drag the heavy object across the room, a guystander came to their rescue by rolling up his sleeves and telling them how to drag it more efficiently.
by measson April 02, 2018
Get the guystander mug.