Help! I really don't agree with my daughters clothing?

Her nana (dad's mum) bought her a top that says 'i want shoes, bags and boys, NOW!' it also has a zip down the side of it. She's 3 (4 in may) and i REALLY don't agree with it, but my fella wants her to wear it when we go to meet his mum in town tomorrow. I'm not at all comfy with my baby wearing something like that, especially not out and about, what would you do? Also this top is available in sizes 6 months up to 6 years, even as a teen i'#d never even think of wearing something like it, but i know i'm a prude for my age (21 in august), his mum's almost 50 though surely she should know better?