The Enfield Haunting (2015)

S2E17 XANA's Kiss

Title: XANA's Kiss Plot: XANA conjures a shapeshifting phantom known as a polymorphic specter, capable of altering its appearance without needing a host. It employs this trickery to sow discord among the group by impersonating them and stealing kisses. As the episode concludes, Aelita decides to test Jeremy's reaction by kissing him. True to form, he becomes noticeably flustered and speechless.