In stroke play are "give me" allowed?

Quick question, me and my friend played a stroke play game. He was a foot away from the hole and asked if I would give him the putt. I told him that i don't think give me's are allowed in stroke play. Am I wrong? Is there an official USGA rule on this? The rason I ask is because he really stinks in putting and would miss that maybe 1 out of 5 times.