Lil Wayne might have a 15 year old son, who just surfaced through his mother. Keiotia Watson claims in legal documents she had a sexual relationship with Wayne back in June 2001 and he got her pregnant. She says their son -- named Dwayne, Weezy's government name -- was born in February 2002.

Watson went to court 2 years ago to establish paternity and get child support. A Louisiana judge ruled in her favor and ordered Wayne to fork over $5k a month, but he hasn't paid a dime, as s he was never served with legal papers or notified he's legally the father.

Weezy has 4 other children (3 sons and a daughter) with 4 different baby mamas .... the list may well grow by 1.

Source: TMZ