Austin Lyon & Alexander Skårsgard in The Diary of a Teenage Girl (2015)

The Diary of a Teenage Girl is a coming of age story centered around Minnie, a teen artist who finds herself engaged in an affair with her mother's boyfriend, Monroe (played by Alexander Skarsgård). As their affair intensifies, Alexander gets several scenes to strip down, showing off his great chest. He also gets a brief rear nude scene early in the film. Austin Lyon appears in the film as Ricky, one of Minnie's classmates. She attempts to move on from her feelings for Monroe by getting closer to Ricky. Austin gets naked in the film as well. He goes skinny dipping, encouraging Minnie to join him. The two also get a sex scene that leads to more rear nudity.