Sensing Elio’s nervousness, Oliver begins to massage his shoulder. (No, not that one.) It happens near the beginning of Luca Guadagnino’s gay odyssey, when Armie Hammer’s character, Oliver, sweaty from volleyball, pauses to steal a drink from Elio, played by Timothée Chalamet. There’s a scene in “Call Me by Your Name” that I can’t get out of my head.