Get a lawyer. W has shown you for months that she can't be trusted so why would you trust her in a divorce? At the very least go see one for an initial consultation and have them review the agreement before you sign it. She doesn't need to know. Just my 2 cents.
M: 48 W: 45 Married: 16 years D1-14, D2-11, D3-9 BD: May 29 She moved out 2 weeks later with kids Awaiting mediation
