'Til Lies Do Us Part (2007)

Advertising executive Trey Mitchell regularly works late and dines with his ex. That makes his wife Leeza so suspicious she hires a P.I., ex-cop Ethan Woods. But he has a dark past and intends to eliminate Trey by any means and make Leeza his. Dirty tricks and even murdering an observant neighbor fabricate enough proof to break up the couple, but they get back together as darling son Dylan deserves. Ethan now hires a junkie to stab Trey to death, but that backfires. His surveillance equipment is discovered, but he escapes and makes his last move.

Source: TMDb