Non-PRO May offend Spanish to English Art/Literary Poetry & Literature Dominican slang

Hi,

I am reading "This Is How You Lose Her" by Junot Diaz. There is one term that I have not been able to definitively translate that I am hoping someone can shed some light on.

In the book a woman meets her boyfriend's mom and asks her about an affair he had with an older woman.

"¿Doña, es verdad que tu hijo taba rapando una vieja?"

The closest I have come is that the expression literally means shaving something, and must mean screwing. Can anyone help?

Thanks!