Invite Household

I can't believe this is not at the top of the requests, and it's still not included in the game! It looks like a big gameplay flaw to me.
Especially with all the improvements we got in relationships between the Sims, and other great updates bringing more realism to the game, this is ridiculous and makes me not want to play, everytime I want to play with a big family or something like that. I'm losing hope...