Cheating isn't that unlikely. She surgically altered her body in a dramatic way. No boobs to decent-sized ones. We are largely a boob-centric culture. So she is getting a level of attention she never had before.
If someone comes along with twice the stamina as her last guy and/or built like a porn star, why wouldn't she play the field? Guys have dumped flat-chested/no-ass girls for stacked girls and girls are even more into 'size' than guys are. I was working at a fitness center and my shorts gave the illusion of having porn dong. The girls, fitness center employees, that saw it started fan-girling even though my personality and body were the same.