" The main characters relationship is not specifically a love story. You can certainly take it in that direction if you wish, though. Their relationship is defined by two different axes: Affection and Affinity. Affection is how much they like each other, Affinity is how well they agree with each other on moral dilemmas. So they might hate each other, but work well. You aren't going to accidentally end up as your friend's gay lover, it'll be a conscious choice if you go for that. "
(Matt Barton and Swen Vincke video chat)
This seems like a pretty clear acknowledgment of romance.
The fact people could, in theory, create both protagonists with the same gender does complicate the romance content too although if you can't take a hint from the game's box that's one's own fault. Maybe they were afraid of ending up in awkward land if family members played coop and faced the romance discussion(s)? Again, that is peoples' own fault if they can't take a hint from the bloody box and load screen and every other piece of information about the game.....hell, it's in the bloody title...."Original Sin". If they are so concerned about making it family friendly maybe they should put a switch in the character creation portion that asks "Are you afraid of mature content?" and then if people answered yes, maybe all dialogue and every bit of exposed skin(including faces and so on) everywhere could be censored or something.