my boyfriend's cat Abby did that. she'd even pee on us in bed...oh it mad me so mad!! we ended up taking her to his mom's farm and she hasn't had any problems there! still have no idea why she did that. she doesn't do it there! yes, she lives inside!! she will pee in the bathtub, but thats definatelay better than the bed!! Good Luck. ps-sometimes it's just behavioral