If someone is being polite but faking it, you might remark that their generosity or hospitality is false and label them as disingenuous. If you find them irritating but not malicious, you could say that they are self-absorbed or arrogant. If they've done you wrong but aren't trying to hide it, you could say that they are deceitful. These phrases are all good ways to describe someone who is pretending to be something or other: phoney, sham, fraud, quack, joker. Don't feel bad if you find them annoying. They're just doing it differently than you are.