Hurry up and tell the OM's wife..

Quit dilly dallying....

You may have this affair on the ropes if you do..

This means that the OM's wife doesn't know and your wife knows she doesn't know...

WHICH means that the OM is NOT sure what he wants..

EXPOSE to the OM's wife ASAP... Time is a wastin....

Your wife will be mad. Let her be mad. Your marriage can recover from her being mad. It can't recover while she is in an affair..