A couple of observations about the OP. Your wife's logic is ill founded from the very start. Why would a registered sex offender be interested in messing with the OP? In all likelihood, no sex offender is going to ever try to rape or molest another man (outside of prison). So, concealed carry isn't going to help you there. And since your wife has made up her mind not to carry, regardless, it's not going to help her either.
But, there are plenty of legitimate reasons for carrying a gun. So, second, don't tell your wife when you are carrying. There are plenty of small 9mm's and .380's that can be carried easily without anyone, even your wife, knowing. 5 years from now, when you get careless and she discovers that you are carrying a gun, you can tell her (truthfully) that you've been carrying for the past 5 years and she never once knew or complained.
In my opinion, there are things a man (or woman) can do without having to consult or even inform your spouse. Carrying a gun is one of them.