Corrected entry: Once Lily finds out Marshall has accepted the judgeship, she is brought a drink and reveals to the group, "yes this has booze in it, no it's not my first." However, later in the season we find out Lily was drinking non alcoholic drinks the entire time because she believed she was pregnant. (00:01:50)
Correction: I think she wants to show how upset she already is, like a "don't mess with me" warning.
Correction: Or she just lied to keep people from assuming she's pregnant? Pretty sure this isn't a mistake and that it's just a lie Lily told the group.
There was no reason for her to lie though. No one asked her what she was drinking and she just randomly walked up to the group and said she was drinking alcohol.
Madiking
I agree with the corrector; Lily lied to her friends. She is hanging out with her very best friends that she sees everyday, knows her drinking habits and she is not ready to share news of her possible pregnancy (esp. Before telling Marshall). On top of it, they would be really suspicious if she had a non-alcoholic beverage and she was free as a bird since Marvin was with Marshall. As a person that tried to hide a pregnancy in social settings, I made it known that my coke was a rum and coke (even if no-one asked).