My husband said all those same things. You cannot change their minds so don't even try. Just smile and say, "Maybe you are right." Then add, "Don't worry honey, I'll find a great step-dad (or step-mom) that the kids will love. Someone they can really adore".... and in your case Brad I'd add, "Maybe one of your friends so we truly can have great vacations together. Hey, you have anyone to set me up with?"
Stuff like that used to throw my husband for a real loop. It was always funny to see his reaction.
There is no arriving, ever. It is all a continual becoming.