Islamic veiw on infidelity...?

Salam aleikum brothers and sisters. My husband and I have been married for 6 months now, and I received a text message from his ex girlfriend saying that she came over to my house and performed oral sex on my husband. I did not believe her at first, but then she went into explicit detail about the entire thing. So I confronted him about it, and told him that if he was honest with my I would forgive him. He confessed to everything. I don't know what to do about this information however. I need to know, islamically speaking, what is right for me to do. I love him with everything I am. And I try my best to be a good wife for him. And I have never stepped outside of our marriage. I just don't know if I can/should stay married to him after he has done this. Can anyone tell me if there is anything in quran or hadith that speaks of this? Thank you.