It seems to be a combination of things First off, hhe person he was having an affair with has ties to Chinese Spy agencies (not sure the ties, but either way, not a great look for someone trying to be deeply involved with America's government)

It also sounds like it was known something was going on with foreign agencies and Jensen, do this puts it out in the open and clears the air.

Lastly, if anyone was trying to use the affair as leverage over him, the best way to break the leverage is to just come out and spill the tea yourself (so to speak)