Their romance isn’t on ice! Ariana Grande and Ethan Slater — who met on the set of their upcoming flick Wicked — cheered on the Florida Panthers to victory over the Edmonton Oilers in Game 1 of the Stanley Cup Finals in Sunrise, Fla., on June 8. “They looked so in love,” an eyewitness says of the couple, who sported Panthers jerseys. (Ariana, 30, is from Florida, while Ethan, 32, hails from Washington, D.C.) Not to be outdone in the PDA department, the next day, Ariana’s ex-husband, real estate agent Dalton Gomez, 28, went Instagram official with actress Maika Monroe, 31, as the two were photographed snuggling aboard a yacht.…