According to the lyrics, they aren’t exclusively complaining, they’re telling “good stories” about their not-so-great experience which is a different thing. Also, they never tried to be a ‘good guest’ at parties, merely that they were found to be ‘interesting at parties’ because of their ‘good stories’.
That said, I really wish they didn’t repeat lyrics so much and instead told more of those “good stories” they keep boasting about.
It does kinda create the illusion of soapy bubble filled white water. If you change thinking about the ‘white water’ section to actually be the see through part in between clear round water droplets (the ‘bubbles’) that are clinging to the side of the container.
It’s most likely someone recently poured some water out of it from the spout at the bottom and what water is left on the sides from the former water line slowly makes its way down to the new water level.