Caught my dirty slutty wife fucking our big dog

I came home unexpected and found my cute 23 year old wife being pounded by our big Boxer. They both were really into it and I must have caught them at the moment they both climaxed. I watched, unnoticed while he got what he wanted and so did she for my wife must have come four or five times. Before he finished he got his balls into her and they were hung up for a while. When he finally pulled out he was longer than me with BIG nuts (which she apparently loved). Finally I let her know I had been there for a while. Since then I have permitted it to continue for I have gotten used to watching and enjoy watching my wife have a good time. Now she wants me to let him do me. I am thinking about it a little.