I had a similar problem, after six years of marriage i told my husband that i was turned on by bdsm. The only thing he knew about bdsm was very advanced and extreme and mostly had to do with the S/m aspect of it. Because of this he wasn't interested. Until i was able to explain to him that it only goes as far as both people are comfotable with. Perhaps you could get your wife to start slow, for example, letting you tie her up while you are having sex. If she can understand that it doesn't have to be all or nothing then she might be more willing to give it a try. Let her know that if she tries and doesn't lke it then you are willing to let it go, but you would realy like it if she would at least try some things. Just remember that unfaithfulness isn't condoned. I would be shocked if anyone here told you to get your kicks elsewhere. We have a very poor view on cheating. Just talk to her and let her know that it doesn't have to be ovewhelming, she is the one who sets her own limits, and you do not cross those limits.