"The full depths of the human psyche and human emotions are a little outside my wheelhouse." It was exactly the reason why Howard tended to prefer machines and no-strings relationships to real emotional attachment. And yes, he was getting in deeper and deeper with Mary, but part of him, a part that was growing smaller every day, still believed that it wouldn't last. Her husband would show up, with her kid, and he'd exit the picture so she could have her happily ever after. Or maybe one of them would be taken away in a heart beat, the way so many others had.
"If I thought it would help, I'd offer to set him straight on that, but he isn't particularly interested in speaking to me and if what Mary has mentioned of my future parenting skills is true, I can't say I blame him."