Sure, she plays it cool on the show ... but "Big Brother" host Julie Chen says she's well aware of all the disgusting racist comments being made inside the house ... and she's offended.
Julie and her husband, CBS honcho Les Moonves, were leaving Craig's in L.A. last night when we asked how she felt about houseguest Aaryn's racist comments about Asians.
"Personally, I was offended," Chen told TMZ ... "I was offended by all the comments -- the anti-gay, the anti-black, but especially the anti-Asian ones ... for obvious reasons."
Still, Chen says she's hopeful Aaryn will be able to "change the way she thinks" after she leaves the BB house.
Chen does take one thinly-veiled shot at Aaryn when asked about the houseguest being dropped by her modeling agency -- check out the clip.