Well I think the difference is a matter of age and time together. BIL is 32 and SIL is 30 and they've been married for nearly 10 years.
Whereas I am 29 and oh is 25 and we've only been together 1 and a half years. Plus he is their baby, the youngest by 4 years coz his other brother is exactly same age as me (older than me by 4 days). I always think that they think I am pushing him to do all this coz I am older but thats not it at all!! We both know we want a baby, and I was even sceptical at first about getting married again just yet but then thought well I love him, why shouldn't we?
Plus my oh claims that his parents were over the moon for us last time they just don't show emotion like my family do, which is like normal people!! Maybe I just need to get used to the fact that his parents aren't as emotional or as enthusiastic as I'd like.
They love BIL and SIL's 4 kids though and dote on them so they'll be ok in the end.
Btw this opening ceremony is surreal!!