It obviously depends on your friends.
If they are good Catholics boys, no problem.
If they are secular people, it could be dangerous. Impure sights and conversations are frequent among male teenagers.
I mean, if you go to somebody's house and have no adult supervision, it is natural to think that the boys might show their favorite "models" to their friends. Impurity is everywhere these days.
Apart from this, the ambient that we live in influences us in many subtle manners that we don't even realize. The more you spend time with secular people, the less you will be inclined to religion.