I would prefer "You have a pice of link on your pants" because the first sentence implies that your pants are not an inatimate object. You are the owner of the pants, the pants do not own themselvs. For the second, I don't have a preference. I would use both of the phrases.

Got it Laura, Many thanks and have a nice day.

For the second sentence, you could also say "we have a twin room at our hotel", as British hotel rooms are often named after the type of bed they have in them. A twin room has two separate beds, a double room has one large bed for two people and a single room has one bed for one person. The exception is that a family room is for 3 or more people.

Oh yeah I forgot. Thank you

Howdy Kai, In both cases both options seem fine. However, you may want to note that in English the word "pants" is plural. As such you would need to say "Your pants HAVE a piece of lint on them"