General von Klinkenhoffen is a thoroughly nasty piece of work, to the extent that friend and foe alike have a tendency to try to assassinate him. Boorish, overbearing, exploitative towards teh French peasants, sexist and lecherous, the General is also greedy and treacherous. So, of course, are most of the cast, but the General carries it off with rather less style than some of them.
Most of the cast are at odds with him, but teh General carries a special grudge against Herr FLick. This is partly becuase the General is of the opinion that Flick's fiance Helga is a "nice piece of stuffing," or, as he put it at another time, "a fine example of German womanhood, and sexy with it." And while the fair Helga is not averse herself to charging the power of her suitors with erotic significance, Herr Flick is violently jealous of her and carefully controls the extent to which she is allowed to ply her charms on the General. IN addition to this, the General hates the way Herr Flick, as representative of the Gestapo, continually flauts von Klinkenhoffen's military authority. He would have disposed of Herr Flick a long time ago, and in fact has concocted several schemes to getting him out of teh way (including keeping him sequestered in the dungeon in Helga's underwear, if it were not for Herr FLick's influential godfather.
The Genral himself is exempt from Herr Flick's worse hatred and fury because of his own connections:
General: My wife's sister is Herr Goering's mistress.
Flick: Herr Goerring has many mistresses.
General: Yes, but my wife's sister is the one with the chamois leather underwear.