Don't feel rejected when he'd rather stay home - it's just a guy thing.
When given the choice between going to Sunday brunch with you and nursing a hangover on his couch, the latter will occasionally win.
He requires alone time because he doesn't want you to know how often he gets take-aways.
It's not always that he needs personal space. It's that he wants to watch the game and hang out with friends.
He needs a break from conversation.
He feels like being a slob without you complaining that he hasn't showered or washed Friday's dishes.