Masecheth 'Avodah Zarah (18b) cryptically mentions "מעשה דברוריה" - "The Beruriah Incident" - as a reason R' Meir fled to Bavel. Rashi (ad loc) explains that R' Meir was teasing his wife (the noted scholar Beruriah) that she would one day admit that the rabbis were correct when they said "נשים דעתן קלות הן" - "Women's intellects are light" (my own translation, but its actual meaning is subject to dispute). To that end, he asked one of his students to "test her to a matter of sin" (presumably this means to seduce her sexually). After resisting for "many days", she succumbed, and when "she realized", she hanged herself and R' Meir fled out of shame.
According to the above-linked Wikipedia entry on Beruriah, Rashi is alone in his explanation of the incident, and there is a tradition among Orthodox rabbis to name their daughters after her to defy that story and reclaim her name as a righteous and scholarly woman of Israel.
a. If Rashi's explanation is correct, what was R' Meir thinking?? Even if it was to goad his wife to some non-sexual sin, what about Lifnei 'Iver? What happened to loving and honoring one's wife?
b. If Rashi's explanation is incorrect, where on earth did it come from, and what was he thinking??