Quote from Marshall in Band or DJ
Ted: Still crying, huh? Lily: Yeah. We've tried everything short of a pack of smokes and a cup of coffee. Still nothing but clean dipeys. Marshall: There's only one explanation for this. Marvin has potty-trained himself. He sneaks into the bathroom while we're sleeping. I'll ask Barney to check the tapes. Lily: Barney has cameras in our bathroom? Marshall: Well, I mean, don't you think?