Based on the behemoth of a thread below, we clearly need to start a thread, and then have it made into a sticky, that details when it is acceptable to use the expression, 'It's MY Wedding' to win an argument.
ETA: Edited to include @Jells2dot0
suggestion that many of these apply ONLY when you and your FI are paying for your wedding yourselves; if other people are paying, you do not get to use 'It's MY Wedding' to win arguments on things that involve money -- i.e., regardless of who is paying, you get to choose your attendants, but if your parents are paying, they get a say in the flowers.
(N.B. -- In all instances going forward, 'my' should be read in the plural, because of course the FI gets a say, too)
1. It's my wedding...so I get to choose the religious (or lack thereof) ceremony
2. It's my wedding...so I get to choose the colours of the palette we use
3. It's my wedding...so I get to have the foods I like at the reception, even if that means roasted turkey in July
4. It's my wedding...so I get to choose my bridal attendants.
5. It's my wedding...so I get to choose the centrepieces and I happen to love upcycled, mis-matched glass vases filled with coloured stones and different flowers in our colours.
I'm gonna go with 'not my circus, not my monkeys.'