As the prodigal Cyndi Lauper once said, using the genius communication form of ─ no, no, the genius art of 80s pop, girl just wanna have fun. That's all they really want!
Dick Grayson also, quite sincerely, wanted girls to have fun. Quite specifically, he wanted his girlfriend ─ his wonderful, gift-of-a-human, angel girlfriend ─ to have fun. Hence the club, hence the sequined skirt, hence the onslaught of vulgarly named cocktails. Hence, him watching you from the bar as you managed to find a best friend in a girl you had never met before because he wasn't drunk enough to dance with you just yet ─ not to Duran Duran, at least. That would take another few shots.
He loved seeing you like this. Hair loose and pretty hips swaying so eye-catchingly to the beat. If he wasn't also the incredibly skilled-in-combat Nightwing, he might have to be afraid of other boys looking at you. He was the esteemed protector of Blüdhaven, fortunately, and he had the bite to back up the bark.
He pushed himself away from the counter, downing another shot ─ being a heavy weight was growing expensive and he wished he didn't have the alcohol tolerance of a European teenager ─ and stepping up behind you.
He wrapped his arms around your waist, a grin adorning his lips as they brushed against your ear. "Hey, pretty. You here alone?"