Can Jews Have Sex With 3 Year Olds?
No, neither the Talmud nor Judaism itself permits sexual relations with 3 year olds or other minors.
This misconception traces to Yebhamot 11b, which contains a passage "...Rava said: This is what was meant - an adult male who has relations with a female child has not done anything because less than this three years old is like sticking a finger into an eyeball." Some have falsely claimed the passage in question said "sexual intercourse with a little girl is permitted if she is three years of age."
The age mentioned in the topic at hand related to whether a woman abused or injured at such an age is considered a virgin — virginity factored into dowry of the day. It in no way morally condones nor endorses such acts.
Sources: