Am I obligated to financially support myWife who walked out 2 months ago? Can I take her off my insurance plan?

You may be able to avoid paying her spousal support on two basis - one as you mentioned is if you can prove adultery.  However, adultery is very difficult to prove.  Even if you collect all the evidence you mention, it is still circumstantial.  It's not enough to show that she spends a lot of time with him and spends the night at his home, you have to show that they are having sex.  How do you prove this without pictures of them in bed together?  The best evidence would be to subpoena her boyfriend for a deposition and ask him under oath whether they have had intercourse.  I hope he is not married, because if so he can refuse to answer based on his 5th Amendment protection against self-incrimination.  If he is not married and has to respond, you have to hope he tells the trust and does not commit perjury.  But if he lies, then you use all of your circumstantial evidence and it will be up to the judge to decide whether his denial is credible in the face of the evidence.  The other way you can prevent paying spousal support is to show that they are living together in a relationship analogous to marriage for more than a year.  It sounds like they have not technically moved in together yet, so this may not help, but keep it in your back pocket in case they do shack up in the future.  This will not prevent you from having to pay temporary support in the meantime, but neither will proving adultery, because you won't get to prove the adultery until you get to a final hearing in a divorce and she can ask for temporary support in the meantime and as long as you are in a position to pay it you will probably have to.  She can also overcome the adultery grounds for denying support if she can show it would constitute a "manifest injustice" to deny her support.  In any event, you would still have to pay child support, as long as the kids are living with her. About the health insurance, do NOT cut her off until the divorce is final.  As long as she is your wife you could be held liable for any out of pockets costs if anything were to happen to her.  This answer is given in accordance with the laws of Virginia and may not be applicable in any other state.  It should not be construed as legal advice, as that would require a more thorough analysis of all of the facts involved in a specific case.  If you need further information or assistance, please feel free to contact my office for a consultation. Case results depend upon a variety of factors unique to each case. Case results do not guarantee or predict a similar result in any future case.