Ironically, boob jobs make a lot more sense for women who keep their clothes on most of the time. They're a lot harder to detect through an ordinary shirt that a woman might wear than they are when she's completely naked.
Unless they did the boob job specifically thinking they were going to do something for their porn career, I would think they did it for their own reasons. In which case, it would seem more likely they'd keep the implants after porn (absent some serious health effects).

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