If Chase were honest with himself (he's never as honest with himself as he is with others; part of him feels he doesn't deserve the truth, and another part feels he deserves respite from it)
he would have told himself he was suspicious (despite the fact that he had always had trouble suspecting people, and even House cannot do so much in a limited period of time)
because he knew that his father (who was a gruff and distant old man, who had made a phone call)
never hugged him back.
He had been waiting for a phone to ring.