In a universe full of oblivious people, Mark stands alone.
The first words said to him in the film are "Hey baby" from Lisa. He shrugs it off.
Then he comes over and Lisa grinds him, puts on a sexy dress, some music (apparently, they are listening to the soundtrack too), and tells him that she loves him.
She comes on to him. He rejects her.
She persists. He denies.
Mark makes it clear, nothing is going to happen. Until Lisa pulls out the last trick she has to lure Mark into her clutches.
After he finally pushes her off of him, she responds by by doing nothing. And then of course, Mark finds her irresistible. Lisa, you tricky bitch.