An absorbent undergarment liner including an absorbent material placed in a medial crotch area of an undergarment that is used to prevent leakage of male genitalia onto the undergarment. The absorbent undergarment liner is constructed with a lower outward flared base in which a first lower flare extends radially inward around an inner thigh region of a trunk leg toward the rear of the undergarment. A second lower flare extends radially outward toward an outer thigh region of the trunk leg. A vertical elongated portion extends upwardly and offset from the center of the open fly region of the undergarment from a front panel lower crotch region to a front panel medial region of the undergarment.
