Apparently I have a "hmmm"

So tonight at the dinner table Blake informs me that his friend Domonic has 2 snowmobiles. "Oh really?" I say. "Yup," he says, "Can he and I ride them?" and I said, "Hmmm, probably not." Blake says, "I KNEW you were gonna say no because that was your 'hmmmm, NO' ". I said, "What?" and said, "When you say "hmmmmm" like that it always means no. When you say, "Hmmm" like this it means yes. But "Hmmmm" like that always means no.

I never realized I had a "hmmmmm" Good thing I have Blake to point these things out.