From what i'm led to believe there are 2 love scenes, a lesbian one, and a heterosexual one (if you can call sex between an alien and a man heterosexual).
You basically just play through the game and it will come, just pick the more flirting options i guess... I think at least 90% of people see it. Its right near the end of the game, like 1-2 hours from the end?
Anyway, if you don't want to play through the game, or you just want cheap thrills?? (porn sites are better!), have a look at this link.