If you see that there are unexplained expenses – particularly those that require large amounts of cash (after all, a cash purchase from a prostitute or sex store, for example, wouldn't leave a paper trail) – then there may be a problem. Take a look at the length of your partner's previous relationships. A history of serial dating and lack of commitment may indicate sex addiction. Finally, if you know for a fact that child abuse and/or molestation was part of your partner's childhood, factor it in with the other habits you're questioning. People who feel ashamed of sexual activity may be addicted, so listen to those thoughts. There is help for people who suffer from sexual addiction, and it's believed that up to 5 percent of the American population is addicted. Sex Addicts Anonymous is a good start.