As Peggy opens her mouth to reply and realizes that no reply actually exists, two things occur to her. The first is that Lee is possibly stoned out of her mind. Being stoned is far from something Peggy has a moral issue with, but showing up at your boyfriend's Madison Avenue office for the first time while high as a kite seems a little tacky. (Not that Peggy has never been tacky.) She wonders what Ginsberg would think, if he would even be okay with dating someone who did anything like that. He rarely bothers anyone else about what they do, but he barely even drinks.
The second thing that occurs is the possibility that Lee has defied their expectations as well as their doubts, and is a gorgeous model who is just as bizarre as Ginsberg.
Peggy doesn't have long to dwell on the latter thought before a suddenly-antsy Ginsberg is crossing his arms and interrupting them. “Alright, party's over. I'm gonna eat my lunch now, and it has nothing to do with either of you.” He narrows his eyes at Stan, who is leaning in the doorway with a bemused expression. “Go eavesdrop on someone else.”
It's a convenient out. Peggy smiles in a way that conveys both polite embarrassment and an undercurrent of everlasting exasperation, and says, “Well, it was nice to finally meet you,” before turning and heading out the door with artist in tow. She does Ginsberg a favor and closes the door behind her.