Like being in a cafe, people watching and listening to snippets of conversations,
a local cafe where one might easily bump into friends or make new ones.
Mug Love is what happens in adultMug when nobody's looking, except for with the sort of people who like it when others look. At questions, I mean. Questions. Get your mind out of the gutter.
In all seriousness, I'd call it an essence or a spirit that's everywhere. :)
There's an excellent article about this in this month's publication of Mug Fancy.