When "Heroes" was released, Bowie stated that it was about two lovers kissing in front of the Berlin Wall whom he spotted outside the window of his recording studio. The lyrics directly reference this moment when Bowie mentions "lovers" who are "standing by the wall." And even makin' out is a little bit heroic when you're doing it in sight of the dreaded communists, right?
But the song omits some key facts about the identity of the lovers, and Bowie would not reveal it for years. These weren't two heroic Germans protesting the division the wall represented by shoving their tongues down each other's throats; it was his producer, Tony Visconti, making out with his mistress. Bowie didn't want to reveal his buddy's infidelity to the world, so he omitted the identity of the "heroes" in the song. It wasn't until years after Visconti divorced his wife that Bowie let the cat out of the bag.
In conclusion, it's probably better for all parties involved that we ignore the "cheating on your wife" thing, lest we confront the fact that we've been equating first responders to guys with hoes in different area codes.