[2][3][4] Ronnie, a loner who lives with his possessive mother, is deemed unfit for military service due to his history of mental instability and petty crime.

Retreating into the world of extremist internet groups, he creates a vlog channel, from which he decries what he describes as the downfall of "real America".

Meanwhile, prompted by sexual frustration, he agrees to play the role of cuckold in a couple's homemade amateur pornography, for which he is financially compensated.

[6] Lambert and Varkle screened actors who could balance vulnerability with volatility, ultimately settling on Zachary Ray Sherman, who gained 45 lb (20 kg) for the role.

[10] Variety praised the "strong performances and atmosphere" of the film but described Cuck as an "overlong" and "downbeat drama" with a "contrived" plot.

[11] The Guardian writer Charles Bramesco favored Cuck to Todd Phillips' 2019 film Joker, calling it "more repellent, honest and astute than this week's odds-on box office champion.