It wasn't that Lethe lacked social graces - well, all right. Maybe it was. Despite her mother's best efforts, often enough she showed herself to be her father's daughter, although without the well-developed sense of decorum. It didn't occur to her to introduce herself because she wasn't used to talking to gods who didn't know her. It was all mortals (who didn't necessarily need to know who she was, especially if she was dealing with them socially instead of professionally) or family, generally.
If anyone at the bar beside Loki noticed Lethe's hair moving, they didn't say anything. Although they were probably having a hard time remembering that it was moving long enough to think much about it - details about her seemed to escape their minds. The bartender remembered that she tipped well and that she liked to sip a double of SoCo and lime instead of shoot a single. But after she left, it was unusual for anybody to be able to remember her features well enough to describe them.
Lethe didn't like to leave a trail.
When he said his name was Loki, recognition sharpened her gaze, and she nodded, slowly taking a sip of her drink.
"You're famous," she said evenly, watching him with keen eyes. "Me too."
Then it seemed like a new thought struck her; she put her drink down as though she'd just remembered something.
"Right, sorry. I've been out of context for a while. I'm Lethe," she said, extending her hand to shake his. "I'm not as famous as you, but mortals like to write about me."
A sardonic half-smile curled the corners of her mouth.
"Why are you here?” she asked, again, forthright but not aggressive. Lethe didn’t see any reason not to be direct.