Last spring I organised a surprise party for my flatmate Lucía's thirtieth birthday. We share a flat in Valencia, and she'd been working very long hours at the hospital, so I thought she deserved something special. The party was in a small bar near the beach that has a back room you can book for free if you order food.
Planning it was harder than I expected. I created a group chat without her, which meant I had to be very careful not to mention it at home. I contacted her sister in Madrid, who agreed to take the train down, and about twenty friends confirmed. The trickiest part was getting Lucía to the bar without suspicion. In the end I told her I'd had a terrible week and needed her to come out for one quick drink, which was half true. I also had to hide a cake in our neighbour's fridge for two days.
When she walked into the back room and everyone shouted, she froze for a second and then burst into tears, partly because she was so tired. Then she saw her sister and completely lost it, in a good way. Later she told me it was the first time in months she'd felt looked after rather than looking after others. Honestly, that reaction made all the sneaking around worthwhile. I think the surprise worked because it wasn't about expensive decorations; it was about bringing together people she hadn't seen for ages. The only downside is she now keeps threatening to do the same for me.