Does THIS Ever Happen To You???

I don't know what's going on here.  It happens all the time...especially when the weather starts to get warmer.  I pour a lovely glass of lemonade, chilled with just the right amount of ice.  I take a few sips, set it down, go do something constructive -- like make dinner, or fold clothes...and then I come back and it looks like this...  Nobody else seems to know what's happening either... Hmmm. ;-]