As far as I'm aware at the moment, there really *isn't* any indication what kind of combat sex will be done to you, aside from the pose you get put into and what the enemy is maybe. As far as the demo goes, the only enemy that can combat rape is the Roper, even though if you DO go to the goblin ambush with sweat status active they get the little dick symbol that shows they can perform battlefuck, just they never actually do it.
Its battlefuck so far, as said above in this post there is the Roper enemy at the moment who can do a few things to your character, the farthest it goes being oral with the rest being outerplay, but the battlefuck mechanics do exist in the game. You just have to initiate it by either being in the pheremone/sweat state (a naked torso in the status bar for the player character) or have it induced by an enemy. (like the roper who can do a mist/fog effect on you which either auto triggers it, or progresses your sweat/pheremones state further than normal, not really sure which as I purposefully just let myself enter the state typically so far.)
In other words, for the most part and if you come prepared, you can pretty much avoid battlefuck entirely if you want, though I wouldn't doubt it if more enemies down the line have the ability to circumvent your lack of hygiene to enable it, and can just trigger it through their own means.
