Q&A How do you Know if Someone is a Sex Addict?

Dear Rick thank you so much for the work that you do and for taking time to answer questions. My question is how do you determine if someone is a sex addict? My husband had 3 affairs over a 22 year periods. The first 2 where only about sex according to him and each lasted about a month and he was the one the ended the relationships as soon as the women involved started taking about the relationship becoming more. The last one was about 7 months and was emotional first and then physical. In the past he has viewed pornography and occasionally gone to strip clubs. But neither of those things where on a habitual level. He says that sex is a way that he relieves stress. One of the most shocking parts for me and an area I am still working on is the fact that he could just use a woman in that way. He has taken some on line quizzes and get mixed results as to if he might be a sex addict. Thank you for any assistance.