Why do people do this?

well i guess its common if youre friends are married and have kids. normally they would tag along kids. if friends bring other friends without ur knowing, i somehow dont like it too. it'll change ur plans sometimes or cant share too much in front of an unknown person or someone u havent invited.

Here in the Philippines only those unprofessionals or uneducated Filipinos do that.

In our country this is not common and it is considered extremely rude. None of our friends would bring their adult children without asking first.

I think if i wanted to bring someone extra, I'd mention it first.

I dont go with mom or any relatives when they have an eat out. Actually, this happens a lot in our country, no matter where, city or countryside. Bringing children can be seen most in newly married couples who has kids under 10. Most of the children dont want to join eat out with parents's friends also when they start understanding things. For newly meet couples, the girl mostly bring along some of her friends if the boyfriend invites her for the first eat out. This may be still happening but will be no more soon since people becoming more individual (Please take this as an Asian thinking) But i was once again learning a new thing that in your country people also bring children with them when they have eating out (actually i didnt think that)

There could be two ways of looking at it. Either they are too close to you so they dont shy away from bring others along. Or may be they are opportunist, who want to make best use of occasion.

That's very inconsiderate of them - I would make it clear next time that you are only inviting them

they bring folks 'long with 'em?? how truly odd's that? fer myself, i'd find that a bit beyond rude :(

I never heard such a thing!!!!! When I make plans for dinner or dinner and a movie with friends, it is with them only. If they had guests, they wouldn't make plans, but rather choose a different day. I think that is not only awful, but rude as well!

I think you need to make it clear exactly whom you are inviting when you make the call. This is absurd.

In our culture it is considered disrespectful when someone asks you to just bring only this number of people with you... lol So, basically everyone is invited... so get prepared...

Yes the civilized way is to ask if they could bring a someone along first. Its also because the host will be making arrangements for Invited people and will be embarrassed if not able to serve all the people well.... In India its customary to bring their friends and family and we welcome it with open heart... Therefore when we Invite 10 we prepare for 20..........