Ask First
That cake in the refrigerator may look yummy, but you should never help yourself to food or drinks without asking. Few things will irritate a person more than to expect to eat something and then realize houseguests have already helped themselves.
Asking first also applies to who you bring with you on a visit. Don't, for example, bring your child's friend or your new beau that you just met a few weeks prior along for your visit without asking permission first. Your hosts may not feel comfortable with strangers — no matter how polite — staying in their abode.
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