Iggy Azalea and Charli XCX’s “Fancy” provided the soundtrack to Saturday night fever throughout the summer, but the morning-after anthem was delivered by Sam Smith. The Brit singer’s huge, hymnal-like hit “Stay With Me” rose to No. 2 on the Billboard Hot 100 and established the 22-year-old as a star. It also opened the door to some of the weirder experiences that come with fame. Ahead of his show at the United Palace Theatre on Thursday, here are four things Smith has learned from sudden success.

Much of the singer’s album “In the Lonely Hour” was inspired by heartbreak: Smith, who is gay, fell in love with a straight man who did not reciprocate the emotion. Fame means that not only do perfect strangers ask him about his personal life, but that the former object of Smith’s affections is fully aware of the feelings the singer had for him. “He’s reacted very maturely, which is refreshing,” Smith tells The Post.

Smith met Queen Bey at the VMAs and she told him that he had a voice “like butter.” “She was incredible and exceeded all my expectations,” he says, clearly still buzzing from the experience. “I can die happy.”

The soulful singer was seated between Miley Cyrus and Katy Perry at the MTV awards last month and looked a little overwhelmed at being in such a bizarre sandwich while the pop circus unfolded in front of him. “I was completely overwhelmed and felt like a fish out of water,” he admits.

Smith’s love affair with the US is just getting started, but he’s ready to test the relationship. “I’ll have to bring out a crap song to find out if you’ll stay with me,” he says. “Mind the pun.”