One difference between humans and animals is that we can exert control over our urges. You are married and my opinion is that entails being faithful to your husband. You did stand up and vow to do so, right?
So I think you have two choices.
1. Control your urge.
2. Talk to hubby and tell him you are horny for a woman and ask if it would be ok if you cheat on him with a woman. If he is fine with it, then have at it.
(I would highly suggest choice #1. Morally speaking, I think it is the proper choice. )