Given the budget limitations ($80,000), "Spanking the Monkey" manages to hold interest albeit with some poorly chosen scenes.
The core of the movie is the relationship between mother and son. The rest of the cast exists to point the way to the inevitable.
The philandering, materialistic, self absorbed husband/father illuminates the barren marriage.
The fumbling sexual attempts of the son with the girl next door and her contradictory accusations of his sexual attempts as either too rough or not rough enough (gay), understandably confuse the son and provide the mother with a mentoring, nurturing sexual role for her son about how to sexually succeed with women.
The mother, stumbling upon a bedroom sexual session between the son and the girl next door, reacts more in jealousy than in any maternally disproving fashion.
The mother's flirtatious ways with the male neighbors, doctors, and ultimately with the girl next door's father point out that while she may be her son's mother, she is still a very desirable woman in the eyes of the rest of the male world.
From the beginning through the end, you never believe the son and mother ever had a mother/child bonding. Both of them are intellectually superior, highly educated. The mother was young when she gave birth and she thinks of herself as her son's educational, intellectual and ultimately sexual mentor, not his mother.
The teenage son's inability to "spank his monkey" combined with the boredom, liquor and medications downed by his mother provide the explosive elements that are just waiting to be lit. The mother's seductive smile and a slight hiking of her nightgown set off the explosion.
This movie is nowhere near perfect, but it's compelling enough to let you sit through the unnecessary (e.g. stoner friends) and that's a lot more than you can say for most movies with a budget that is a thousand times greater.
