IR and weird roll-playing?

Ok I have a situation and would like sum feedback.... I'm a 23 yr old Italian- American guy and I recently started renting a new place. I'm sharing it with this unbelievable delicious roomate. She's a 22yr old Beautiful OVERTLY ual African American girl. (I know every guy's dream right!!!..... pretty much!!!) She's a self-confessed -aholic. ANd we Have a LOT of . Were not exclusive.... or even dating.... but if were in the Apartment at the same time were basically having . I look at it like a rollercoster and I'm jus tryin to enjoy the ride but, she is like a lil bit crazy.... she yells out crazy stuff....she bites.....she ches the hell out of my back (like I fought a Lion and lost) which is all fine and dandy..... but she also wants me to roll play ......where she's a y slave girl and I'm like a horny white slave owner. (very wild) She gets REALLY INTO This!!! but...it makes me feel really weird!!! But I don't want to mess up a good thing..any thoughts??? Advise?