A movie in the early 80s, where I think "3" kids get abducted by aliens, that are friendly aliens. One alien is pudgy and bug eyed, and starts singing the theme song to Mr. Ed. The aliens knowledge of earth is only learned through television. There is a sassy female alien.

Sounds like Explorers (1985) (http://www.imdb.com/title/tt0089114/)

Thank you Blue Angel. Totally relieved myself trivia stump. Exactly the movie that is was thinking of.

Happy to help.