We see the actors—Martin, LaBeouf, others—engage in many, many acts of unsimulated sex (i.e. full penetration).
Then at the sight of his pale and harassed face she recoiled in evident and unsimulated surprise.
1620s, "feign, pretend, assume falsely" (implied in simulated), back-formation from simulation or else from Latin simulatus, past participle of simulare "to make like, imitate, copy." Meaning "to use a model to imitate certain conditions for purposes of study or training" is from 1947. Related: Simulating.