DEAR ABBY: My 17-year-old son wants to go to the prom. I am on disability and my husband drives a tow truck. We are barely surviving, but how can we tell our son he can't go to the prom?

The prom tickets are $60 and the tuxedo rental is $100. Then there are the shirt and shoes, a corsage for the girl and breakfast the next morning!My husband and I have talked it over and we've been cutting corners trying to save the money a little at a time so our son can go. He's a good kid and deserves to go.

Every week it's something else. A yearbook, a class ring, a field trip - we just can't keep up with all of this. Some of the girls are flying to New York to get gowns! And the boys' parents are renting limousines for the big night. Where is it all going to end? - NO MONEY MACHINE

DEAR NO MONEY MACHINE: Nowhere is it written that parents must foot the bill for prom night. The seniors know a year in advance that there will be a senior prom. Some kids line up after-school and weekend jobs to earn their own prom money. Your son may be a good kid who deserves to go to the prom, but when money is tight, some kids earn the money themselves.

DEAR ABBY: "Gladys" claims that her longtime relationship with an older man was OK because although there had been intimate touching, passionate kissing and telephone conversations two or three times a day, they never had sex.

My husband was involved in a similar relationship for three years. She was 23 years younger than he, and they, too, swore there was never any sex - they were just "good friends." Bull!

Even if you believe these two liars are not having sex, the betrayal of the marriage vows is clear. ("Cleave unto each other and forsake all others," the Bible says.)

I didn't believe my husband either, but I chose not to divorce him. After he found out that I was wise to him, he said he no longer sees "that slut," but his credibility has been so badly damaged, I no longer believe a word he says. There are days when I want to throw him out, but then I recall how much I loved him before all this happened.

My husband's girlfriend is also married, but her husband is mercifully in the dark. Sometimes I itch to tell her husband in order to shatter her world as she shattered mine; then I think of all the innocent people who would be hurt, and I back off.

What do you think? Should I expose the affair and get my revenge? My therapist says I should think only of myself and tell.

I can't sign my name, but I feel much better getting this off my chest. Thanks for the friendly ear, Abby. - REVENGE IS SWEET

DEAR REVENGE: Revenge is not sweet when innocent people are hurt in the process. You say you are in therapy. Good! Have you given any thought to marriage counseling for you and your straying spouse? In spite of his occasional lapses of fidelity, since your marriage is still intact, methinks it could use a routine tuneup.

1991 Universal Press Syndicate