Sven is inadvertently stumbling into "nice guy" territory, [...]

What the ... what ?!?
He genuinely seems to believe that being honest about your feelings will make things work out how you want them to do.
Well OK "nice guy" isnt exactly a clearly defined term in the first place, but still I dont see how "being honest about your feelings" fits into any definitions I'm aware of.
Nice guys are typically thought of as people of low self esteem, overly sensitive/feminine, they end up too easily in the friend zone of girls they fancy, they are respectful towards women (at least they think so) while the girls they fancy end up with douchebags, etc.
If theres anything Sven doesnt lack is confidence. And he isnt very sensitive at all, either.
if he follows faye inside I will be dissapointed in him.
I would bet Faye would get really angry at that point. I think Sven knows that too.
And now Svens journey to the dark side will begin.
OMG he actually joins a side now ? I dont think so.
Something about Faye's rejection isn't convincing. I'm probably just reading into it, but it's really because she said "I have a boyfriend!" instead of "I'm too happy with Angus to leave him for anybody".
Why, yes !
I think you indeed definitely do read too much into it.
Faye's version got to the point much quicker then your unnecessarily much more longwinded one.