Rose Byrne has been hitting the talk show circuit to promote “Neighbors 2″, in which she and Seth Rogen reprise their roles from the hit comedy, and last night saw her take a seat on Stephen Colbert’s “Late Show”; couch.

Byrne is also a new mom, and explained that all the additional travelling she’s been doing recently has been taking its toll.

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“It takes a long time to leave the house, maybe an hour, hour and forty five minutes just to get out the door,”; she said. “You have to bring the bottle, the sling, this and that. Then when you get out, then he just throws up everywhere or takes a big poop and you’ve got to go back inside again.”

Travelling with her infant son has meant that she’s “been taking my breast milk everywhere with me,” she noted… at which point Colbert showed viewers a photo of Byrne at the airport as TSA officials were confiscating her breast milk, because it was more than the limit of three ounces.

“They wave this weird thing over the top of it and there’s this production going on,”; she explained. “I just stand there and smile and tell them that it’s really breast milk.”;

The Late Show with Stephen Colbert airs weeknights at 11:35 p.m. ET/PT on Global; you can also watch full episodes and interviews online.