I think that you DEFINATELY SHOULD NOT tell her!
What if it ruined everything?
What could possibly be worse than messing up a perfectly good relationship.

Please be careful! Once it's done, you can't unsay it.

Personally, if I was female and your wife and you told me that, I'd be shocked, betrayed and well pissed off!

but of course it's up to you!! I hope whatever you do turns out ok, but I don't see what good would come out of you telling her.

I can only think of bad points.

I also have a fantasy (strictly) of sucking cock, but I would never do it, and never let anyone know!!