How to catch a cheating husband

What do I need to prove adultery? Are text messages okay if he admits it? Or does he have to write a letter admitting what he did? Or do I have to hire a private investigator? We are already separated and living in separate residences and separate counties. Help!!

Any evidence you have that he admits the affair will work in your favor in court. The more concrete the evidence is, the better. If you are already separated, hiring a private investigator may not be beneficial as they can only prove what is happening now, not what has happened in the past. While evidence of post-separation behavior can be used to corroborate pre-separation behavior, it may not be worth the expense. I suggest you have a consultation with an attorney in your area to discuss the specific facts of your case and make a plan on how to proceed.