Hello and welcome!
I am sorry for the pain you have been enduring.
I give you a lot of credit for reaching out to look for information and for support.
I want to be honest with you. I do not want to further upset you. I think I can help you best by telling you my truth. I fully believe that there is a root issue within your marriage, which comes out whenever your wife is feeling less inhibited. (Many people living with BP illness go through periods of feeling less inhibited.) I strongly encourage you both to seek couples counseling even if, at some point, the goal becomes the intention of pursuing a sane separation for eveyone's sake.
Both my husband and I have been diagnosed as BPII. I have never even considered cheating on my husband, physically,nor emotionally. I have never gone over the line. I have never lied to him or disrespected our vows to one another. (I have BPII illness.) It's been very different with my husband. He has head repeated episodes which were very close to infidelity and more. When we would go to couples counseling, he'd always blamed his illness. Too often, the marriage counselor would allow this explanation/excuse. Over the years, this pattern had kept repeating until it became worse each time. He has never been dedicated to our marriage, rarely honored our vows. But remember, we are both diagnosed with BPII illness. Again, there are often root causes which have very little, if anything, to do with living with BP illness.
I wish you and your family healing.