Your paths crossed for a while. You took a vow with someone who's no longer there. You're free to explore 6 billion other people. Have fun...play safe.
I am sure his wife will be absolutely delighted at you passing on this attitude to her husband of ten years! You describe her marriage as a temporary crossing of paths - how absolutely crass!!
We have heard one side of the story here. He has not told us of any efforts to try and reconcile, only whinged about not getting any. His wife might be ill, worried, depressed or a hundred and one other things. Until he asks then he'll never know but looking for a substitute before any avenues have been explored WITHIN their marriage, then that's pure selfishness in my eyes.
Marriage is not all about sex either, hugely important though that is. Most people enter into marriage for a long term commitment. Many people have all sorts of reasons that interupts a sex life they once enjoyed - ask anyone who's partner has been incapacitated through illness or accident etc. Do they all give up on the marriage because they can no longer have sex. Thats an extreme example but if people can carry on under such adversity then you owe it to your wife to try and sort this out. The same as she owes it to you to listen and talk back. One of you has to initiate this conversation - be the bigger person and YOU start that dialogue in a non confrontational way. She might be happily riding your cock for the next 20 years once she has been allowed to express herself without fear of being rejected! Women are very astute - do you think she hasn't realised her marriage is in trouble?
All I will say to you is TALK before you seek sex elsewhere because if your wife ever finds out then that will put a wedge between you thats far greater than her revelation that she doesn't like her pussy licked. Did you bother to ask her what you do that turns her on? No - I think you acted like a spoiled child having his furry toy taken away. She didn't refuse you sex in Vegas - from what I have read you can't get over the fact she has told you about ONE aspect of your sex life that doesn't appeal to her and thats all you cane home in on. She didn't say anything to you for ten years. Would you have liked her to continue for another ten years participating in a sex act shes not keen of?
Move this on and come back and tell us what you have done to make things right, not what you are going to do behind her back if she doesnt come up with the goods!