What would you do if you caught your husband with a cyber fling?

i discovered that my husband was chatting everynight with this woman for more than 2 months now. the woman makes him videos, calls him besfriend.. and is being sweet to him...telling him that he's always in her heart and thoughts. she sends him email every now and then. i don't know if between them is platonic or not, but do i have the right to interfere with them? I am afraid that this friendship would later on fall into love.. was my decision of confronting the woman online the right thing?