She wasn't born yesterday.
You can't fool her.She wasn't born yesterday.
Don't try to cheat me, I wasn't born yesterday.
A:Susan,do you want to drop by Tom's with me tonight?I hear he's having a party.
B:I wish I could.But I promised to run errands for my mom.I don't think I can get out of it.
A:You could tell her something important came up.
A:You could say that an old friend turned up and that you wanted to see her.
B:I don't think she'll believe such excuses.She wasn't born yesterday,you know.Maybe I can come later on.