What's the song Uncle Jesse sings?

This is probably a really strange question, but in the first or second season, Uncle Jesse opens up an episode of Full House with his band. It’s the Chicken Pox episode when he didn’t think he could get chicken pox and got it from Stephanie, which prevented him from going to the performance he had later that night.

I absolutely love that part of the show, just because it reminds me of the Beach Boys a little, and I like older music more than I do now. And that song they sing is great.

Now I don’t know if it’s something they just wrote for the episode or if it’s a real thing, but can someone help me find it? I just love it so much.