Thanks for your input everyone. I spoke with the groom and he said that there was a blanket rule no children at all allowed. I said that DS is very quiet and wouldn't create a disturbance but he needed to be with his mum. He said that he's asked his sister not to bring her children (not sure of their ages or if they have local sitters) so I therefore can't bring my DS. The groom offered to find a baby sitter for DS - and I was like NO WAY! He didn't seem to understand that I wasn't happy to leave a 4 month old with someone I'd never met before...

So it was a choice between DS AND me or neither, and they chose neither. It's their wedding so ultimately it's up to them, but it's not a decision I would have made... Still, at least I won't have to sit through the speeches! LOL.