The only woman you can't compete with is the dead one.
Conversations are like sex. You either want it or not... You can not force another person to speak to you, to open up, to share the most sacred, to share pain & joy. So the deeper the conversations are, the more often it happens, the more connected people feel no matter how great is the distance.
I see that you posted this question a month ago now, so I hope you haven't done anything you regret about it.
If this is still relevant, discuss everything that bothers you. Define your goals as a couple, your freedoms: what is acceptable and what's not.
Define what exactly you consider as cheating and what consequences should it be.
Discuss your reputation as a wife.
See, your husband can be saying around how wonderful you're as a life partner, but does his ex have this great impression of you?
A jerk has no bad feelings humiliating a partner.
A King holds his Queen on her throne.
16 years is a long time together. No one today wants to stay married for solely survival reasons. Marriage is like an emotional enterprise where faithfulness is a choice and Love is the main motive.
Faithfulness is not biology.
It is a value created by homo sapiens ( or "wise men").
This is why Family has always been and always will be in great value to us as wise species, and for evolutionary reasons.
Is this still your husband’s value? Does he feel proud of what he has, what's been accomplished during all this time?
Because if not, be ready to let him go.
It's better to be honest with each other, it's better to relieve each other's sufferings (if that's how it feels), it's better to speak up about what's wrong etc., than to continue living unhappy together and pretend that everything is fine.