Desmond Scott’s mystery make-out partner — yeah, the one he was locking lips with just two days after we broke the story his estranged wife Kristy hit him with divorce papers — has officially been identified.

Sources familiar with the situation tell TMZ the woman getting hot and heavy with Desmond last Sunday is Marissa Springer, a 24-year-old local Houston model who’s also currently in school working toward her master’s degree in business.

We’re told the two met for the first time earlier that night at Houston bar Sante through a mutual pal … and Marissa had no clue about Desmond’s online fame. Our sources say it was also her understanding that he was single at the time.