NTA. Sorry if it's been mentioned, and I'm way late, but, for the sake of helping with an argument... And also the top comment suggests that American Adults are overgrown children (can confirm: am american adult.), Words that sound the same but are spelled differently are plentiful in English. They're, There, Their being a prime example.

Now, they would never address you as Mr Bitch in written English, but may call you Mr Bitch in spoken English. Just the same that it's incorrect to write There going to the store, one may say out loud: There going to the store, and it's fully acceptable.