Oh, Ellie - that's wonderful! I love the museum, too, but don't think I have ever had a tantrum about going!
I haven't had kids, but a story my Mum used to tell about my sister - when she had a tantrum - anywhere- she would lay on the ground and hold her breath until she turned blue! The poor passers-by used to think Mum was so cruel!
In case you think I was too good to be true, I can think of something I said to embarass my poor Mum. We had visitors for lunch one day (old family friends, and supposed to be a quick lunch) and Mum did beans on toast. I asked her, in front of everyone, if it was the tin of beans she had scraped the mould off earlier! She almost curled up with embarassment, but luckily the friends took it in good humour!