How to make water taste like vodka?

My mum & dad have a bottle of vodka in our cupboard at home that they never drink. But me and my friends drank it so I filled the bottle up with water. But then I remembered that one night every christmas all the family comes to my house and my parents get the alcohol out and I'm gunna get totally busted if they realise it isn't vodka. So I need a cheap and easy way of making something that tastes/smells like vodka or a way of not getting caught. Please Help?!?!