Bazza, you can eat whatever you like, it is the quantity that is the problem.
Butterkist Cinema Sweet Popcorn has 68.5g of carbs per 100g, but that's a lot of popcorn so say 10g is about 7g of carbs, that's OK if you don't swill it down with a can of orange juice or something.
Just count it in with your evening meal and make sure you don't go to far over your daily target.
I often eat things like jam (no added sugar) chocolate (80% cocoa solids so less sugar) chips (only about 8 ) and so on. I don't eat lots of any of them. Just a taste from time to time or life would be boring.
My favourite treat when going to the theatre is nuts, hazelnuts, walnuts, pecans and so on.
I shell them first so as not to disturb anyone else, then they can easily tell if they are making a noise with their confounded sweet wrappers!
H