"Not emotionally secure enough"??? This is not the ST I remember from my childhood. Also I agree that he says "Kicky", which is less disturbing yet possibly more confusing.
I watched this on PBS (1yo son) and "Not emotionally secure enough" came across to me as one of the many funny little lines they put in Sesame Street for adults who are watching. There are a lot of lines like this. I imagine they were there back when I watched in the early 80s, but I wouldn't have caught them as a 5 year old.
I'm voting for "kicky". However, the last couple lines are pretty unambiguous and are enough in themselves to validate the folks who think there's some kind of innuendo here.