Is it okay to book a double room for three people in a hotel?

I'm trying to book a hotel in Paris and Venice. I have two other girls with me, and we want to save money. Will hotels allow you to book a double when there are three people staying in the room? Thanks!

I don't know about paris and venice but its done in the states all the time.....most of them have two double beds so one with 2 people and l alone.

Some won't but what they don't know won't hurt em!