My husband has had multiple incidents of infidelity usually saying he doesn't know why he did but regrets it. Any insight into understanding this

That’s incredibly painful especially when trust already feels fragile, and even more so if you're living with BPD. Feeling intense emotions, fear of abandonment, or struggling with trust can already be overwhelming and repeated betrayal only adds to that weight. When someone cheats more than once and says they “don’t know why,” it can mean they’re avoiding real accountability or lack insight into their behavior. Regret doesn’t always equal change and without real reflection or action, it’s likely to keep happening. You deserve consistency, safety, and honesty, not confusion. If his actions keep hurting you, it’s okay to ask yourself if staying is helping you heal, or reopening wounds. Therapy (individual or couples) can sometimes help, but only if he’s truly committed to change. Whatever you decide, your feelings are valid. You’re not “too much”, you’re just asking for what you absolutely deserve: love that doesn’t hurt you.

It makes sense that you are feeling confused, hurt, or even exhausted trying to understand something that has affected you so deeply. When someone repeatedly crosses a boundary, it can leave you wondering what it means about the relationship and about your partner’s behavior. Many people who engage in repeated infidelity struggle to explain their actions, and hearing that they do not know why can feel even more painful because it provides no clarity or direction. Your need for understanding is completely valid. What matters most here is acknowledging how this situation impacts you emotionally. Your feelings deserve space and respect. It can help to focus on what trust and safety mean to you, and what you need in order to feel supported moving forward. You are not wrong for wanting answers, and reaching out to talk about this shows real strength.