SPOILER ALERT: This column contains spoilers for Season 3 of “ Heartstopper ,” now streaming on Netflix . The first two seasons of “Heartstopper,” Netflix’s popular YA series, were about falling in love. In Season 2 of “Heartstopper,” viewers watched the quiet and unsure Charlie Spring ( Joe Locke ) and his new boyfriend, the self-assured and protective Nick Nelson ( Kit Connor ), navigate their new relationship.

In Season 3, in episodes revolving around mental wellness, sex and significant life changes, creator Alice Oseman — adapting her own graphic novels — focuses on the work relationships require, and what it means to thrive or perish as new feelings and expectations are unearthed. Sex is a major theme in Season 3. Charlie and Nick have sex for the first time, and their friends, Elle (Yasmin Finney) and Tao (William Gao), also take their romance to the next level.

However, Oseman doesn’t simply offer up gratuitous scenes of teens allowing their hormones to get the best of them. What she presents are thoughtful conversations around insecurities, sexual wellness, privacy and the emotions of sexual intimacy. “Heartstopper” Season 3 opens three weeks after the Season 2 finale.

In the final month of the summer holiday, Charlie, Nick and their friends head to the beach. Though entirely smitten with Nick, Charlie obviously isn’t doing well mentally. For the first three episodes of the season, audiences watch as his mental health and eating disorder con.