Avoidant. (FA and DA) Have you had experience with them being vindictive and holding grudges?

Over the last 4 years with my FA, off and on of course, I have noticed he is very vindictive towards others. He told me of some weird things he did to people he did not like such as wiping his ass with their toothbrush, Pissing in their orange juice bottle in the refrigerator , snitching them off to co workers about personal things they told him, etc...I am worried what will happen when I break it off with this guy?? Is this common with FA/DAs? I have not seen it talked about anywhere?