alligators in the sewers
Use this phrase when you know someone is giving you a total bullshit story, but you don't want to confront them head-on with their ridiculous lies.
Guy #1 - Yeah man, last night I picked up this gorgeous chick at the bar, and we had a threesome with her sister. Guy #2 - Yeah, okay man, blah, blah, blah, blase, blase, blase, alligators in the sewers....