8 XXX : deepthroat

Serious question, how do people establish a "safe word" equivalent in this scenario? Best I can come up with is that this is done by people who already are very familiar with each other's limits and trust each other completely?
Source?
i love to be deepthroated and i love to give messy blow jobs. and hate it when guys says what the fuck is this.. this is disqusting. it is a turn off for some guys and i can not even begin to understand why and how.
So sexy ?
Just shy of trackin that foo down and crackin his bitch ass skull. She’s breathin. B lucky

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