Your baby Belle, is still pretty young. Sometimes adding a new furbaby can cause a few set backs with current trained furbabies. I experienced this with my last three additions, each one about a year or so apart. It only happened a couple times though,as i made sure to stay to a strict potty training schedule and did not allow the new ones the opportunity to have an accident\ and they did learn from the older ones a little quicker.
You mentioned him peeeing on the beds and blankets, are yuou confining him seperately from Belle? and is this in a crate you are talking about or on your bed? I would defenitely seperate them and not allow him an opportunity to have an accident. Not sure how you are training him so its hard to give advice that may be helpful. I don't believe it has to do with dominance as much as hey it smells like pee so i should go here, lol. your baby Belle could be a little upset by the new addition too, hard to tell |