Earlier this month, Kehlani and Demi Lovato concluded the US leg of their Tell Me You Love Me tour by kissing on a rotating stage bed.Mainstream pop is, of course, no stranger to demonstrations of Sapphic affection – growing up, MTV gave us Katy Perry’s “I Kissed a Girl” with all its “cherry chapstick” and “experimental games”, while Madonna and Britney shared an iconic kiss. Classical music and high European…