In terms of entrance and presence, Peter was... well, quiet. And out of the way as much as possible. Lily received countless looks of combined concern and frustration, of course, but he didn't say much to her that might upset her. He wouldn't want to do that.
But he has definitely changed over the years, getting thinner and becoming the bearer of a certain number of scars. He also looks a lot stressed and a lot more run-down than he used to.