a simple relationship over the summer free of hassle and drama

Briefly, "the realization that each random passerby is living a life as vivid and complex as your own." Originally from the Dictionary of Obscure Sorrows, which has a lot more beautiful neologism definitions like this you might enjoy.

a casual almost dating kind of relationship. happens in the warm months of may-september when school is out! usually happens within summer workplaces where students hookup with each other all summer before going back to school in the fall. similar to friends with benefits, except these usually only last a couple of months before they come to an end due to the couple splitting off back to reality.

(see California fling)
A sexual adventure free of hassles, commitments or drama, timed for the summer only. Something light and fun-filled with nothing to worry about at the end of the season. Usually not exclusive to one person, ends in a mutual agreement of friendship.