There wasn't any feeling of obligation on House's behalf but he felt like he wanted to see his son. To see if he was okay. It was as simple as that. He never thought fatherhood would ever come naturally to him but this feeling that he wanted to be there for Jason was something that wouldn't go away. Instead of ignoring it, House was actually addressing it. Maybe he was going soft in his old age.....Finally..
He pushed the door open and spotted Jason immediately. He limped over and nudged him with the butt of his cane. "When I ask you to the pub, I don't mean start without me."