If he's standing in the way of her achieving her goal (true love), then he's also an antagonist. Both Guy and her father stand in the way of her achieving true love throughout the story, so you could profile either one (or both) as your story's antagonist.

The conflict is that your protagonist has to choose between following her father's advice (and the machinations of Guy) and her heart.

You're thinking of complications. Your third guy may be a complication. Is he present in the whole story or does he show up later to serve no other purpose than to complicate things further for your heroine?

Cheers,
Michelle