The action of two bespectacled folks clicking the corner their thick frames together when actually kissing would be too faux pas.
Eleanor and Jude were on their first date at the rowdy bar downtown. When Jude bought her a PBR, she leaned in to kiss him, then rethought it after acknowledging their surroundings and instead tapped the corner of her plastic glasses against his in a hipster kiss.
When two hipsters use telepathy to declare a romantic interest in one another. Words, a peck on the cheek, a reassuring touch, or even a simple smile would betray emotion, thereby running the risk that onlookers might suspect the two hipsters are enjoying the moment truthfully (rather than ironically).
"Lars, do you see how Marius and Clementine are staring coldly at one another from across the room, without speaking or motion of any kind? Do you see how dead her eyes look behind those turquoise spectacles?"
"Yes, Niko, I do. What's their deal?"
"It's a hipster kiss. They'll be engaged as quickly as you can Tweet 'Free art show! BYOB!!' "