Theo held his tongue where before he might have said something; he would have preferred to go to Hogwarts personally, but that was only so that he could escape the inhuman formalities of his house. This route also stopped him from saying something potentially incendiary in the house he was currently in, something about choice and purebloods and half bloods and freedom.
He'd become used to not having his own opinion, so just made a noise of agreement with Draco and sipped his drink again.