@BabyCakes,
God sex life sound good to me
There are alot of questionables about allowing your partner to sleep with someone else, on the inset, you may feel "fine" believing that it won't make him stray or feel any in-different to you.
However, these are the things you have to consider after...
Did he like her more? Was she better than you? Will he now want it again? Do you now feel jealous? Do you now feel that you aren't the only one anymore...not as important....
Will you now look at his facebook, phone, computer? Will you always now be wondering....
It's a dangerous road to go down, especially at your age. It sounds as if you are young and love can be blind... This overwhelming love for someone you would do anything for?
My only advice if you do decide to go ahead, is to ensure it is with a total stranger that you are 100% certain he will never be able to contact again.
However, I'd also like you to look at your personality and ask yourself the above questions because I am betting, at least one of those feelings / thoughts or actions you WILL do, if you go through with it..and it could ruin your marriage in the long run.
How about holding back for 5 years or so, when you are both more mature and see how you think then.
In addition, I'd communicate with him and discuss the porn. The more he sees, the more he wants if you want to do anything, discuss new adventures together, it could be all he is missing not another "body" and ask him to curve the amount of times he is viewing porn out of respect for your marriage.