Mary Kay Letourneau's husband and former student, Vili Fualaau, files for separation

— -- Two decades after an infamous sex scandal threw them into the national spotlight, Mary Kay Letourneau Fualaau and husband Vili Fualaau are separating, according to court documents.

Fualaau, 33, requested to legally separate from his 55-year-old wife and former sixth-grade teacher on May 9, according to court documents filed in King County, Washington.

The two married in May of 2005 in Washington state after Letourneau completed a seven-year prison sentence on child rape charges stemming from her relationship with Fualaau.

The relationship came to light when she became pregnant with their first child. She was 34 and married with four children. He was 13.

Letourneau pleaded guilty to two counts of second-degree child rape in 1997. She gave birth to their second child while behind bars.