Not going to Paris with UB

[nummerfire]

Blinds 100/200, NL, My stack 3000 ( a little under average), first prize worth $15.000 (WPT trip Paris) and four small consolation prizes.

My main opponent (the button) in this hand has me covered, but not by a lot.

I have K8o in BB and 3 callers to me (SB folds).

Flop comes 3-5-8 with 2 spades

I bet the pot (T900) and get raised all in.

I am reasonably sure he has a flush draw, and call.

He had A2 of spades and got there. (Is it correct that with 12 outs he is a little under 50% to win).

Comments on all streets appreciated.

Kim