Terror Within II 
Buy this movie now
Ernie: It feels like my insides are on fire.
Ariel: There's nothing wrong with people needing each other.
Ariel: Stop! Stop right there! Don't hurt him! You're part of him! You're part of me!
Elaba: You have come at last - the prophecy has been fulfilled.
Kara: A mutant sperm of some sort, forcing its way into the embryo, fusing with it, battling for genetic dominance!