Night before last (Sunday night actually) when I was playing the game with my Vampire slayer he was called and invited to Landgrabbes birthday party (the dad) - I had my sim say yes and he was whisked over to outside of the Landgrabbes house where the dad waited for him and invited him in. There was a caterer there baking cakes and stuff. The first one she put candles in and then went to baking more and literally filling the fridge with cakes - lol.
There were a few other sims there, mostly my Sims friends or co-workers and other Sims I also play - but basically it was a pretty boring event. I kept waiting for the dad to blow out his candles and he seemed to do everything but - finally I clicked for my Sims to celebrate - the third time I clicked that - all of a sudden the dad aged to elder. Funny though is he never blew out those candles, and never initiated anyone to take any cake or anything - I finally clicked on the cake and had my sim take a piece - then the other sims there did likewise. Finally the timer for the party ended and the dad said he had seen better birthday parties - so needless to say it was as bad a party as it felt like. LOL. The game does not plan these things very well - and what little was done my sim initiated it with my help.
Odd thing about this birthday party though - I have all aging turned off right this minute - so maybe it was all lackluster due to that, as technically there should not have been any aging going on. I am guessing the AI overrided my game option to have no aging at this time. I found that interesting seeing I have never had that happen without me overriding that by throwing my own party. So I conclude if the game really wants someone to age up - they apparently will regardless of what options we set.
But to answer the question - yep invited to birthdays even with aging turned off for all households.
ETA - I posted this because before I had aging shut off I had also gotten invites to birthday parties too, but rarely went to them - it had been a while since an invite and I sort of thought it was because I shut aging off (mainly to not allow all my households with babies and tots to age without me) so I assumed with aging off there would be no invites. I assumed wrong. LOL.
