Talking to Arima is a huge jump. But not so much the other two. He did have at least a decent relationship with those two, though nothing you could consider even close to being best friends.
And like I said, he's probably in shock. It's definately not something he wants to talk about right now with no one else besides Suzuka. He's just trying to get his thoughts together about what he's going to do and such.
Now if he ends up spilling the beans to Arima, that'd be just about as big bullshit as it was when we found out she was preggers. He's his fucking rival, they've said like a total of 20 or so words to eachother throughout the manga. It wouldn't be smart for Seo to do that.
IMO he needs to have a good talk with Suzuka about how they should handle telling people. And decide during said talk about who they tell.
Bullet Tooth Tony: You should never underestimate the predictability of stupidity.
Reporter on Titan Maximum: Sasha is there any connection between your poor album sales and the fact that it sucked?