Invite Household

I was playing right now and starting thinking about this again. It is such a pain! Specially since toddlers don't seem to hang around lots unless you bring them. I wanted my active family to invite the neighbours for a bbq since they have a kid and a toddler that could play with the kid and toodler in my active household. The parents are already together in a club and hang out regularly, but I wanted a friendly families gathering.
It would also be very useful to make family gatherings and invite siblings with their whole families so your sims would get to know all the nephews at once without having to visit them.