Sisters 21st or partners 40th?

If she was mature about it I might have investigated the costs of moving the trip. As she's behaving like that you're being kinder in the long term not to let this behaviour work.How old are you if your partner is 40 and she's 21, presuming nearer 40, how much fun is it to be with a bunch of 21 year olds anyway. Point out you booked it ages ago, do something nice for her once she shows reasonable behaviour.

Sorry I think I need to add that I booked the Italy trip months ago.

So quite possibly at the time her sister's birthday didn't cross her mind if it was months away. It doesn't make her a bad sister.

Reespectfully, I disagree. When I was that age (well before the introduction of Americanisms such as fancy proms, baby showers etc) your 21st was the main event and a much bigger landmark than turning 18.

And yet none of my mates in the late 90s or early 2000s saw it that way. We were at uni and had a night out at the student union - nothing more special than any other bday in my experience.

Partner of 11 years gets to call shotgun over your sister. BUT as he said he wasn't bothered you were daft to then arrange his trip abroad for your Sister's birthday weekend. I don't blame her for being miffed about it, however she's OTT for not speaking to you.

Go to Italy. You prebooked it, it's already paid for. End of discussion.

A 21yo doesn't need her adult sister there at a birthday party FFS, she's being very childish. If she's so desperate to have everyone there, she can move it to the weekend before her birthday or another weekend that suits everyone.

@SnappyQuoter You don't represent all of us in the Uk.
21st birthdays are still considered big in the UK for many families. In fact, I'm going to my nephew's in a few weeks time.It'll be a big family party with all his friends there too. It's been a tradition in our family for 50 years or more, and nothing to do with American habits at all.

If it's possible to rearrange the Italy weekend, I'd be inclined to do so...however, the silent treatment doesn't seem like a very mature way for your sister to handle this, and if she's normally like this when she doesn't get her own way, perhaps you need to be careful about caving in to her.

Some Young people want everything these days , they want so many birthdays to be special days and it seems to be becoming the norm
13 th
16th
18th
and then expecting the 21 st to be special too !!

But my 21st was for me and all my friends! Proper black tie sit down dinner and dancing. Those were the days!

Definitely a thing. Always have been and I'm in my 60s

Team 40th here too. Lake Como is lovely but expensive so don’t lose money on your trip, your DH takes precedence.

Back to the original question- I think I’d have checked with my sister and booked a weekend after once I’d known there was a party. BUT sulking and not speaking is a bit OTT.

21st has always been seen as a big birthday in my circles. Most of my friends had parties for their 21st in the UK.

“Abuse tactic to manipulate you” because a 21 year old is upset her sister is missing her party. Good lord,

go to Italy. Why does she want a birthday party for turning 21? She should be clubbing with her mates 🥴

Rubbish. 21 has always been a significant birthday. Possibly more so than an 18th. I’m in my 50s, didn’t have an 18th but had a 21st. My mother had a 21st back in the 1950s. There’s an old song about getting the key to the door, never been 21before. It’s always been a big birthday.

But the partner in this situation isn't bothered so it's irrelevant how people would respond to a partner who was upset about it.

I think it was a shitty thing for you to do. Your partner wasn't bothered about his birthday. I'm coming up to 40 and been having friends turn 40 over the last few years, although it is a milestone birthday, none of us have cared about it as much as we did our 21st. Birthday's are generally a lot more important to young people, it's very clear from your post that it is that way with your DP and sister. Your DP isn't bothered, it is very important to your sister, so why did you book something for your DP and miss your sisters party?

21st isn't a big birthday - nothing legally changes, it's just another year. I know it used to be when my parents were young, but someone turning 21 now is 50+ years past that change in the law! I turned 21 in the early 2000s and it was no big deal, 18 is the big one. I would also think it's unusual to have a family party at 21, doesn't she want to be with her mates?

If your partner genuinely wouldn't mind then change the weekend of your trip and do both, but she is being silly.

Can you imagine the responses if someone posted ‘My birthday is the same as dp’s sister’s, and every year he chooses her birthday over mine. He even rearranged a trip abroad to celebrate my milestone birthday so he could go to a party she’d only arranged the week before’

I would have booked the weekend away for another weekend if I knew it was my sisters bday and my Dp was g fussed about celebrating on the day. Why split yourself in two when there was an easy solution?

I just wouldn’t have booked for that weekend knowing it was my sisters big birthday. I wouldve checked first. I love my sister dearly and wouldn’t wanted to have missed a party! I would then have booked an alternative weekend for my Dh and made it a proper surprise- tell him on his actual birthday then go away the next weekend.

Dh could have a whole weekend to himself for his 50th when it didn’t clash with my sisters.

Why? It's his birthday too. Should his always be sidelined for her sister?

If you can easily change the Italy weekend (and your partner fortunately is acting like a grown up and doesn’t mind which weekend you go) then I would do it, seeing it obviously mattes to your sister. It’s nice she wants you there