@Sir_Boops i mean that's mostly because the air's actually warm when it's expelled but because of how FAST the air's moving when you purse your lips it causes any micro droplets of moisture on the skin to evaporate and strips heat off from the surface you're blowing on as a result making it feel "cold". When you're exhaling with a wide open mouth the air is moving relatively slowly so it collects around the surface and thus warms it up with the humidity in your breath.