PJ,
Let me tell you for a sex addict myself, who is fighting off the temptations daily. You need to set boundaries in your marriage. You have already made the mistake by thinking some of this activity is harmless. When it comes to pornography & sexual addiction, the desires increase and are endless. The will get worse if he doesn't abstain and invest those desires into you. He is already spending money and taking it away from his family, which was the hardest thing for me to justify.
He has already cheated on you. What you need to understand is the intent. Our legal system is based our the Bible and the Old testement Law. whenever, the court can prove your intent, you will be convicted. In that smae fashion, his intentions are to cheat. His intentions are to desire a women other than you. He is more self absord, that he doens't LOVE you enough to consider your feelings. If he LOVES you. He will change. However, you can't force him. He needs God. He needs counseling. He needs time to change. You must set up boundaries that demand accountability for his actions. Don't allow internet use behind close doors. Stop giving him all the sex he wants and become detached from him. Explain that he is bring multiple women into your bedroom and see how he would feel if the roles were reversed.
Nonetheless, it is cheating. Don't wait for sexual intercouse to happen before you take it seriously. He has an addiction, as most men do. Try reading, Boundaries in Marriage and Every Man's Battle.
I have a link to my website which will give you some information about infidelity and our Signs of Infidelity checklist.
http://www.Catching-Cheaters.com
God Bless you both and good luck!!! Hope that helps...
Best regards,
Douglas Jarmon-Investigator 4 LOVE
Corinthian Group: Private Investigations & Personal Protection
(877) 687-3939/OUR-EYEZ