Mātuputtika Sutta
Once a mother and her son — a monk and a nun — spent the rainy season at Sāvatthi. They saw much of each other and, in course of time, became guilty of incest.
When this was reported to the Buddha, he declared that nothing ensnares the heart of a man as does a woman; she is indeed a noose of Māra. A.iii.67 f.