Reg for scuba divers who suck dick

For any bottom, male or female.

Make scuba reg in dildo shape. Air holes on sides, a bit away from the end. So diver has to suck the dildo-reg deep into mouth to reach the air holes by lips. Whole time underwater he/she has to keep the dildo-reg deep in mouth and strength lips out to ensure the holes are covered and provide sucker with air.
At the end of dive mouth will be exhausted!

After some time the diver has to "upgrade" to dildo-reg where holes a bit more away, so sucker has to suck it into mouth even deeper and strength lips even further.