Jamadgini was a great sage, among the most powerful of his era. As can be imagined he lived the most austere of lives with no fancy bells and whistles. Revathi was his wife. They also had five sons, the youngest of them being Parasurama(Literally meaning Rama of the axe(Parasu)). Parshurama would later attain fame as the killer of the entire Kshatriya race and for being a supreme warrior brahmin.
Once it so happened that as Revathi was filling up water in the mornings as she usually did, she happened to see Gandharvas and Apsaras frolicking and enjoying themselves. They were beings of such beauty and grace that she could not help but imagine herself amongst them partaking in their activities.
While she was imagining things, the pot in her hand slipped thereby breaking the spell. Revathi was too shaken to make any sense of things. She ran back not taking care of the trees and their thorny branches. By the time she arrived back to the ashram she and her clothes were in tatters.
Jamadgini being the dutiful husband that he was, asked her about the problem. At first she was hesitant but Jamadgini noticed the tell tale signs of arousal upon her face. A short while later she had narrated what she had seen. Jamadgini was full of rage at this transgression.
As each of his sons returned from their morning tasks he called them one by one and asked them to behead their mother's head for this cardinal sin. He promised them anything that they might desire in return for this dastardly deed. The eldest son refused of course. He said that he could not do the deed asked because his mother had taken care of him all his life and he would surely go to hell for this deed. As did the second, third and fourth(They were perhaps influenced by the eldest). Jamadgini grew progressively angrier as each of his sons refused.
Then Rama of the axe who had gone to collect firewood returned. Jamadgini asked his youngest son to behead his mother in return for which he would grant him anything he desired. Parasurama cut of his mother's head without a moment's hesitation. Then Parasurama asked that he wished for his mother to be resurrected.
It is amusing to note however that all mythologies are invariably patriarchal and most such stories revolve around punishments meted out to wives by husbands and the woman losing her chastity(or being suspected of doing so).