Charles Wenzelberg/NY Post/MEGA Selena Gomez and Benny Blanco are engaged to be married, but the couple started out as collaborators. Blanco coproduced two songs on Gomez’s 2015 album, Revival: “Kill Em With Kindness” and “Same Old Love.” The pair quickly became friends, and at one point, Gomez even asked Blanco whether he had anyone he…
