Actually, Paul, it may hurt to ask, especially if you value the relationship.
This is why there's a little heat to the discussion, because, frankly, the written agreement that Rep has with his broker is that he will pay the broker a stated and pre-determined amount, and now, he's threatening not to make the deal unless the broker caves on his fee.
David Ogilvy, famed advertising man of the 50s & 60s, wrote a book, Ogilvy on Advertising, a good read even for real estate agents. In it, he discusses how to negotiate the best deal with an advertising agency:
Pay them 16%, even though the going rate is 15%. The one percent won't make much of a difference to your bottom line, but it will double the profit for the agency, making you their most important client and ensuring you get top priority and the very best service from them.
Few people ever think that real estate brokers should ever get paid more . . . until you consider that maybe, just maybe, it's worth paying a premium to have a valuable Realtor on your side.