When the cell membrane catches a phospholipid trying to flip from one layer to the other without using proper transport proteins... 🚨 FLIPPASE POLICE! 🚨
That phospholipid thought it could just casually cross the membrane bilayer on its own? Rookie mistake. The hydrophilic head can't just yeet itself through the hydrophobic core without enzymatic assistance. That's why we have flippase enzymes - nature's bouncers keeping the asymmetry of your membrane intact since 3.5 billion years ago.
Trust me, I've seen phospholipids try this move in my 40 years of cell biology. They always get caught. Membrane integrity is no joke - unless you're an anime character in a hazmat suit, apparently.