Lovin' Spoonful trivia: I've read this story; does anyone know if it's true?

Supposedly, Sebastian secretly married one of Zal Yanovsky's ex-girlfriends. Zal was upset by this and, famous for his onstage antics, put a rubber frog in front of John's face while John was trying to sing. This happened when they appeared on the Ed Sullivan Show. Did anyone actually see this? And who was the wife/ex-girlfriend?