He wants to have sex with you.

"Meat curtains" is guy slang for labia (you know, your vagina lips). Saying a girl has big meat curtains is usually derogatory as it's not exactly the most attractive feature of a vagina. He was probably just teasing you though.

If he wants to "eat your meat curtains" then he wants to perform oral sex on you. If your mom doesn't know either it's probably best not to tell her what they are either, since then she'd know about your boyf wanting to do you.