Or they could just behave like adults… People fancy other prople all the time and it’s not reciprocated.
She’s told him, you’ve told him. If he were to continue, it would be unwelcome and a matter for HR. Should this blokes career be messed up just because he misread the signals?
If you know him, arrange to meet him. Tell him in a grown up way (no headbutts, no threats, no urine, no forks of any make) that his interest is unwelcome and you and your wife would prefer him not to pursue her/it any more.
Neanderthals, tsssk…