You mean the background music ? It is Park Mi Sun- You are Lovelier than Any Day. You can find it on Spotify We…
Thanks a lot, but I've meant the background song when they are drinking beer...found it finally: https://www.youtube.com/watch?v=_P31Fezdvig ...a rather generic retro pop song, still somehow charming ... Maybe they used it because of the lyrics "We can do anything that we wanna do Long as you got me and I know I got you"
Long as you got me and I know I got you"