Re: every sim can grow up from toddler to elder by blowing out birthday candles
I'm not sure I would consider this a bug. Yes, multiple sims can blow out the candles and keep aging up for as long as you want them to. Having multiple sims blow out the candles on the same cake works great for twins and triplets (better than in Sims 3 where I had to buy two separate cakes to age up my twins on the same day).
The question that I have is why would you have the same sim blow out the candles more than once unless you want them to skip a certain age and go directly to the next. Which isn't a bug, it's a choice. The solution would be to have the sim blow out the candles and then not do it again.
Now, there is the issue that you can have the birthday sim blow out the candles (which causes them to age up) and make a wish (which also makes them age up) which to me doesn't make sense since traditionally on birthdays, you make a wish and blow out the candles and only celebrate one birthday. So not sure why Sims makes both of them an aging trigger.
But again, you can choose how many times your sim blows out the candles. Here's a tip, don't put more candles on the cake after your sim has blown them out. That way you're not tempted to blow out the candles more than once.
