Is this an acceptable thing to do?

Hi,

If I'm selling on a classified site. Customer orders, and I want to order it from elsewhere and let them directly ship to my customer (suppose walmart), now my customer would know I didn't have the item and I just pass on the order to walmart, also they would see a cheaper price on the box (suppose my dropshipper can't do it as a gift). My question is, I want to let walmart ship directly to my customer, would my customer get mad at me or would they understand this is my business model….

Is this an acceptable thing to do?