She's cheating on you OP. Here is a copy paste of what you should do:
If your looking to protect yourself i suggest following this. A lot of my friends got married immediately out of High School so i figured this wasn't a bad idea to hold onto. This is a raw copy paste.
Divorce – If proof positive of infidelity
• get a PO box, and new email account, start redirecting anything of significance to the PO box and email account. Go through all types of online shopping and delete accounts or at least remove stored credit card information (did you save your credit card info at Amazon or the Apple iTunes store?)
• get a Google Voice virtual phone number or some other service and start redirecting your accounts from everywhere to that phone number. Later you can also use this for contacting your lawyer for all the preparation before you tell her about it.
• get a NEW checking account (with that PO box address) at a different bank and start transferring money out - when you are ready LATER you can redirect your auto-paycheck deposits there too. Long term savings and IRA's and 401k's need to have all passwords reset and addresses changed to PO box.
• get a safety deposit box at the new bank. You can start storing valuable documents, expensive small items, and cash there. Store cash there as much as you can off the record (and don't even tell your divorce lawyer).
• take pictures of everything that you think can be used as evidence of lying, cheating, infidelity. If you can afford it, hire a private investigator to start collecting information (including if she has been hiding accounts, money, or debts from you). You need to find out if she has credit cards or other debts and start disassociating yourself from them (you may end up being responsible for them anyway, which is why you need to start transferring money out of your accounts now to pay for them later after divorce is final.
• hire a professional but cheap accountant to help you start measuring things up. Accountants are a dime a dozen. You can find an independent one that can run a full and complete credit check on you to find anything out of place. You can also get this accountant to put a lock on your profile with all three credit agencies (deny all new credit/borrowing).
• inventory of all your possessions (yours and hers) of any value (sentimental value or monetary value). Make a list, estimate value, and take pictures (with serial numbers). If they are tiny (jewelry, expensive coins, watches, then take them to the safety deposit box. All these documents that you are collecting, and memory cards from the camera should be stored in the safety deposit box.
• once these things are in place, you hire a divorce lawyer before you even tell her anything and prepare to file. When you are ready, go ahead and file - THEN TELL HER and just walk away. Depending on your state the chances are that either she is for certain getting the house or that the house will be calculated as part of a 50/50 split of assets and she will get to keep the house. That whole War of the Roses movie type "stay in the house and fight for it" is BS. It doesn't work that way.
........ I completely skipped anything about dealing with the relationship at all because in my opinion (I'm flawed) once she cheats, I'M DONE. The relationship is over for me with no chance of reconciliation ever EVER. I'm just angry at that point and will pursue getting away without getting ripped off (which is what happens to most men in a divorce).