It might've been better off left out completely, it just seems a little off. You would think a person, any person, would worry about STDs before they hop into bed with someone--anyone. I know Seth loves Jacob, but it's implied that he's a whore (Jacob, I mean) and if that's the case, Seth would know Jacob sleeps around and there's the possibility of contracting an STD.

Now that I think about it, if there was that danger, I would think Seth would ask Jacob to wear a condom too. Y'know? But the story's already written. No sense in changing it now. I just wanted to point that out.