Keeping information from a partner is not considered good behavior.
Jim is married and his father passed away and left him an inheritance.
Jim wants to buy a second home.
Jim and his wife buy a vacation home together.
Jim buys a second home as a bachelor pad to bring dates back to and doesn't tell his wife.
Jim's wife will be happy and feel appreciated by Jim.
Jim's wife will divorce him when she finds out he's cheating on her.