Wife

I have recently discovered that my husband of 8 years has had multiple affairs throughout our marriage and probably our entire relationship. He thinks it is a sex addiction. How can I know if it is or if he is just unfaithful and never committed to me? it sounds although over the years things have escalated from flirting, through to kissing, sexting etc ending up with multiple sexual affairs It is only in the last few years that things regularly became sexual. Does that mean that it was not a sex addiction in the early years but now is? Or did he just realise over time that he could get away with affairs so did more and more. I am not even sure if it matters if he was addicted or not I guess cheating is still cheating but I just can't make sense of how he could do this for so long when he claims he always loved me.