Cheating on my wife with her best friends 19 y/o daughter while currently living with them.

Recently my wife (26) and I (26) began living with her best friend Amanda and her 19 year old daughter Christy. Last weekend my wife and Amanda went out and Christy was out with her friends leaving me hone alone. Around midnight Christy came home in tears which caused me to ask her what happened. Long story short she found out her boyfriend was cheating on her. After talking for awhile she went to bed.

The next evening My wife and Amanda went out again this time leaving me and Christy home alone. An hour after they left Christy came out in the living room wearing just a long t-shirt. “I decided what to do about my boyfriend” she said. “Whats that?” I asked. She smiled and said “im going to do to him what he did to me”. When i didnt say anything she went on “look, I heard about your wife cheating on you and I figured this is a win win. You get even and I do to.”