With boys I can attest that taking them shopping is torture for all involved. Little boys do NOT like going shopping for clothes, even if the clothes are for them.
I have come up with a "method" for shopping. Once I verify the size, I just throw everything of that size I can find into a shopping cart. I then buy it and take it home. Once home, I have the kids try the clothes on by threatening them with grounding for the rest of their lives. When at home, there is no one to complain about the noise level the boys make with their complaints about trying everything on. Items we don't like or that do not fit then gets returned to the store. I have found that once I started using this method, the boys and I are no longer banned from stores!
Today #3 asked me why we were going shopping. I let him know that it was so that I could torture him mercilessly. The store employees who overheard me were quite amused.