What the hell do I do?

I've been my wife for 4 years she's an attorney and I'm a ironworker She tells me her firm hired a new paralegal for her this was three months ago. So we finally met at a office party at a local bar & grill the other night. Turns out her paralegal is ex-girlfriend. who apparently still has feelings. My wife doesn't know that night was awkward and it still kinda is. Do I tell my wife? And what do I say? This kinda shit can turn UGLY as hell.
What the hell do I do?
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