David begins to moan, his skin is hardening into an aliens, while his muscles and stiff member get larger and larger, his skin becomes jet black, his mouth becomes mandibles, and a alien tail emerges from his spine.
Mary gazes at his new form and feels her sex start to leak fluids all over," Now, let us mate in perfect union!", she screams.
David inserts his cock into her over sized pussy and begins to rock back and forth, both of them moaning in unison, suddenly he feels the lips of his cock begin to open while in Mary's vagina, her vagina is pushing eggs into his cock!