THINGS MUST BE GOING pretty well in the military if one of the bigger problems facing this man's and woman's army is "sex fraternization"-the hugging and kissing and worse between different sexes of different ranks. The problem was illustrated in a story in Monday's Post by an army law officer, who explained how difficult it is to run an organization when the person with whom you slept last night orders you to clean the latrine this morning. That officer clearly knows very little about the insitution of of the army here, where the wars are other-directed.

At issue is army discipline, which evidently is seriously threatened by what an official report last May referred to in a gratuitously picturesque phrase as "a creeping advance" of hanky-panky. There are at present 720,000 men in the army, compared with 49,000 women (the comparing accounts for some of the trouble), creating an alarming ratio of almost 15 to 1, or 15, depending on which way one creeps. Last spring, Staff Sgt. Darryl Stewart was court-martialed or fraternizing with Pvt Cheryl Bernard, his financee. Protested the sergeant: "I love here and i love the army" -indicating that he was at least half crazed at the time. Still, regulations are regulations, and the current regulations expressly prohibit "any nonprofessional, social relationships of a personal nature" between NCOs and trainees.

Naturally, the army isn't about to advocate professional social relationships of a personal nature, so it has itself in a bind. Just how thight the bind can get is demonstrated by the case of Beth Larkin, a 20-year-old army cook at Fort Jackson, S.C., who was recently charged with "bringing discredit to the army" for having worked as a topless waitress in columbia. According to the prosecution, Miss Larkin, who faces six months at hard labor, was topless for a full seven mintues.) Had Miss Larkin been allowed a bit of fraternization or, better still, affection back at the fort, perhaps she might not have been drive to such extremes of misconduct.But love is where you find it, and not in the army