His sister the boyfriend

...Zoe." "Zoe?" gasped Jon. "God I hope Biff and Sarah weren't in the middle of doing it when we swapped." Zoe grimaced "Well I don't remember doing that, just waking up as Biff now." Jon nodded "Same here but considering we don't know how we swapped how do we know we haven't just blacked that from our minds?" "Can we please change the subject?" replied Zoe, pulling a face "How do we go about swapping back?" "I just hope we can; no offence but I don't fancy having you as my boyfriend."