I know I probably am.
DH is one of three, I like both my BILs very much. Eldest ones is in a long term relationship with someone who has made it very clear they don't wish to marry or have children which is entirely their choice. Youngest was married very young and divorced very soon after, this was before DH and I met. Has been in a relationship with a really lovely girl for several years, they live some distance away so we see him seldomly, and her less so as they both have very demanding jobs, which is a shame but just how life goes - I love seeing them when we get the chance though and he's brilliant with our children.
They have returned from holiday and announced they married whilst away. I'm sure they had good reasons for doing it this way and it is entirely their choice, but I can't help but feel sad and a bit cheated that we didn't get to share their special day - I am so happy BIL has found someone lovely after being treated badly by his ex wife and I'm pleased for them, but still - I'm sad.
Also a teeny bit jealous that new SIL sidestepped having to have MILs horrendous family at her wedding whilst I took the full hit of crazy...