I can always tell when my girlfriend is about to cum from the pressure of her hands on my head. When she is pressing down hard holding my head on her cock like a flesh light, I know I am about to get a load.Heavy cummers are always a fun treat. I go back and forth between wanting a warning and being surprised/shocked when a massive explosion occurs. It's awesome to know ahead of time and pull it out and be soaked in a cum bath. But a sneaky massive load choking me and making me struggle to contain it is fun too.