Bringing someone back to the hotel?

Hey. I dunno where to put this. Im from London but im going to Milton Keynes in 2weeks time. Im staying at a hotel by myself for a week because i don't wanna stay with my friend because id rather be by myself. Im just wondering, are you allowed to bring someone back to your hotel room for the night? Someone who isn't staying there. Do they allow this? Thankss =]