Sources said the couple were "super cute" during the film, with Gomez putting her "arms around [The Weeknd's] neck."
Gomez and The Weeknd were first linked in January following the singer's split from model Bella Hadid, and enjoyed a romantic trip to Italy the same month.
The pair stayed just minutes away from Hadid during a visit to Paris in February.
Gomez and The Weeknd "speak and text all the time," an insider told E! News.
"They both didn't expect this to go as fast as it has, but it's fine by them. They are both happy and have a great connection, physically and mentally."
Gomez and The Weeknd have yet to publicly address their relationship.
The actress dodged questions about the "Starboy" singer in the April issue of Vogue, where she also discussed her life as a former Disney star.
"Look, I love what I do, and I'm aware of how lucky I am, but -- how can I say this without sounding weird? I just really can't wait for people to forget about me," she said when asked about The Weeknd.
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