Can I sue my spouses partner under Alienation of Affection

My simple answer is - you can sue anyone for almost anything, the real question is will you win. Alienation of affections is extremely fact sensitive. What you need to do is talk with an experienced family law attorney and go over the facts of the case. I offer an initial 1/2 hour consultation for the cost of $50, or check out other attorneys. Just make sure that they are at least aware of case law where alienation of affections has been upheld. I know that I am.