How hard is it to understand that Sue and her personality could very easily see the Surfer as a lost soul, and want to help him. He in turn is attracted to this beautiful, sympathetic woman who is far different than what he thought humans were all about. Reed could see his (surfer) as a physical attraction/ along with their competition as scientists.
To me thats not that hard to comprehend happening, nor is it that bad of a storyline. I think it would be cool, and VERY IN CHARACTER for this to happen.
In my opinion, that as part of the storyline wouldn't be a negative.
If thats not what they have written in the script then Ben being in the love triangle (i hate that term) won't work.
If they have taken directly from the comic, then ok, Ben needs to be the one along with Alicia. I don't think they've gone that direction, and therefore Sue, I think, is the best one to befriend the SS and show him that not all humans should be devoured. "so to speak" In that scenario, Sue is a much better character to do that than Ben.
I'm sorry, I just don't see this as a "love triangle" scenario, no matter what some may call it. I didn't think it was a "love triangle" in the first movie either. If people thought it was, then I have a very different definition than they do.