We don't know a lot about his relationship with Madonna's daughter, Lourdes Leon. Chalamet has been notoriously bashful about his love life in a respectful but infuriating way — we want the tea!
Allegedly, Chalamet met Leon at LaGuardia High School in New York City in 2013. While it's unclear how long the pair dated, it seems like Chalamet's first public remarks about dating the "Papa Don't Preach" singer's daughter didn't make headlines until 2017. During an interview with Andy Cohen the same year, Chalamet seemed to indicate that he and Leon are still great friends. He said that Leon expressed being super happy for Chalamet during his Call Me By Your Name success. In the interview, he said, "She hasn't seen [the film] yet, but she's excited to. ... She teases me about the public appearances... the movie itself she's very excited about, and the reception it's been getting is only a great thing."
Cohen and Chalamet actually met each other on a dance floor at a party before Chalamet was as famous as he is now. Cohen recalled that rendezvous, remarking that Chalamet and Leon were a "super cute couple," made even cuter by how excited Chalamet appeared to be when he mentioned being able to get down on the dance floor with Madonna, who was also at the apparently star-studded soiree.