Given his mournful bleating about how all his friends have gone down in flames because their adult responsibilities and need not to short-change their children conflict with his Liz-like refusal to let go of childhood things depress him and make him see cool people be replaced with boring old people who talk about boring old people stuff like having to work in the morning and seeing kids off to school, you might think that we're dealing with another dreary man-child who's got commitment issues. You might also think that since Elly and John are the only married couple he interacts with on any regular basis, he's stupid enough to think that the Pattersons are a normal family and the giddy bungle the two self-absorbed drips make of things is How Parenthood Should Be. There is that but there is something else: Elly's overweening need to drag him into the stupid soap-opera she'd made of Connie's love life.
If she hadn't tried to arrange things so that Phil would be made into an insta-dad with an insta-life so that he would be punished for being happy and loved while she was treated like his slave, Connie would be happy (and also not threaten every marriage in Christendom), Lawrence would have a father and Ted would be thwarted despite Connie's marriage and Ted's misery eventually happening on their own anyway, I think it's sort of obvious that the only real sticking factor to his proposing would be his parents telling him to act like a man and make an honest woman of Georgia. Since they're not as insistent about things, he and Georgia would have probably gotten married about a month or two after they moved in together because he wouldn't have been messed up by the whole Connie debacle AND he wouldn't have a destructive asshole sister screwing his life up for him with her endless meddling. Simply put, Elly's life and the lives of those around her would be better if she'd just lay the Hell off and let people live their lives without her useless interference.