If you ever want to be invited back to someone else’s home, houseguest etiquette matters. No host wants to welcome back a guest who criticized them or left their house a mess. So it’s important to be respectful of one’s space to maintain amicable relationships and score another invite.
Unfortunately, this guy completely ignored basic courtesy when coming to a friend’s home. Not only did he make fun of the buddy’s humble abode, but he also expected to let him crash there after a few days, for which he got a big fat rejection.