Just got moved to the must move and cover everyone. Im sitting on a huge stack and youngish asian so might be perceived as aggro.

BB (hero)- AsTsAd6d
MP - 2.5k
BU - 800

SB is the rock (10$) i raise in the BB to 30. MP (no history but looks like a young pro) 3b to 90, BU (played with him a few times, def a rec player, can be super passive or aggro) calls 90. I decide to 4b to 370 thinking MP will fold alot bc i can get the 6b in. MP calls BU calls.

Flop comes Kh 9h 4s

i decide to check, MP checks very quickly, BU goes all in for about 440 ish.
i flat (BIG mistake?)
MP calls (leaving behind 1.9kish)

Turn is 2c

i donk pot putting MP all in.

Im curious to what you guys think of my line. Thanks