I live in a "no fault" state; however, according to L if you have proof it will assist in the division of assets. I am now going to work on getting proof (i.e. pictures).
I would either double check with your lawyer or get a new one. The only thing infidelity provides is "cause" to get divorced and/or waive mandatory waiting periods for no-fault divorces. It has NO impact on custody or financial issues. The only thing it can do is provide leverage in your negotiations if she doesn't want to air her dirty laundry.
So why torture yourself with pictures? Think about it.
Everybody hurts. It's part of life. Don't miss the good stuff.