Cupcakes gone before cake cutting.

Maybe don't bring out the whole display until you're close to cutting the cake?

See if your venue can keep most (if not all ) the cupcakes in the back/kitchen until it's time. That way no guest has access to them before the cake cutting ceremony.

I have a sign that says

"Treat yo'self
Dessert bar opens after cake cutting"

You could do a sign, but honestly, you cannot control other people. We had cupcakes, they were displayed the whole time. If anyone took them before dinner, I didn’t notice but we also ad TONS of leftovers.

I get being worried about this but try to focus on the big reason for the day and your time with your husband. People will inevitably do something stupid or rude and if you worry about all of those things, you won’t be able o relax and enjoy your wedding day.

I would literally never do that but some people have zero couth. I went to two weddings with cupcake display and I didn't notice if anyone took them early. I don't think they did. I went to one brunch wedding that had a donut display and because it was brunch so many people were taking them before the bride and groom did. That was their dessert! People can be rude. I agree with making a sign that says something like "wait for the mr and mrs"! You could also have the dj announce that cake cutting will be after dinner and to please not indulge in the cupcakes until after the cake cutting!

Don't put them out until they're ready to be eaten. I am close friends with a caterer, at one wedding she was trying to do a chocolate fountain display, and had put it out to set up but it needed 15 minutes to get going (so the fountain was still doing its chocolate thing but not well, think lots of gaps and runny bc it isnt in full swing yet). She's used to putting desserts out when theyre ready to be eaten and walking away, not needing 15 minutes. She said it was awful, kids coming up and trying to use it, her telling the parents its not ready yet and having PARENTS try to use it AFTER being told. Note she was standing there telling people not to do it and they still. were. doing. it. A lot of times people think if its JUST them its fine and forget about the waterfall effect. I've never been to a wedding where if there was more dessert than cake it was put out in advance, you will need to expect its eaten, even if told not to. At a wedding I was just at, the guests were instructed to wait outside the tent at the cocktail area until the bride and groom arrived. That lasted for about 20 minutes, and then it was a 50/50 split of people being in the tent or in the cocktail area. If they had desserts already out under the tent and expected them to be fine because no one should have been in there, guarantee they'd be munched on. Since you said you don't have the option of waiting, I'd say you either have to recognize the cupcakes will be eaten even if you tell people not to, and tell your photographer to get photos fast, or do your cake cutting very quickly like pp suggested. Only other thing I could think of is if the cupcakes were on those little glass tiers that have glass lids, if there is a sign that says not to and people have to take a lid off to get to it, I feel like that'd be a huge deterrent, while still being pretty.