Flopped flush + Open Ended Straight flush draw,

[grouchie]

Party Poker No-Limit Hold'em, $ BB (10 handed) converter

UTG+2 ($24.75)
MP1 ($20.38)
MP2 ($25.25)
MP3 ($24.05)
CO ($19)
Button ($26.9)
SB ($23.87)
BB ($54.3)
UTG ($25)
Hero ($45.2)

Preflop: Hero is UTG+1 with 5[img]/images/graemlins/diamond.gif[/img], 6[img]/images/graemlins/diamond.gif[/img]. SB posts a blind of $0.1.
<font color="#666666">1 fold</font>, Hero calls $0.25, UTG+2 calls $0.25, <font color="#666666">2 folds</font>, <font color="#CC3333">MP3 raises to $2</font>, <font color="#666666">2 folds</font>, SB (poster) calls $1.90, <font color="#666666">1 fold</font>, Hero calls $1.75, UTG+2 calls $1.75.

Flop: ($8.25) K[img]/images/graemlins/diamond.gif[/img], 7[img]/images/graemlins/diamond.gif[/img], 8[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(4 players)</font>
SB checks, Hero checks, UTG+2 calls $22.75 (All-In), MP3 folds, SB calls $21.87 (All-In)

Hero....?

I only have 5 hands on UTG+2 thus I really had no idea what his all in was representing. I know some people make this move with 2 pair or trips to chase out someone with the A.

I have about 50 hands with MP3, but up to this point he has done nothing that stands out. He's played a couple of hands, nothing to showdown.
So, unfortunately There are no reads.

I know people will say fold preflop, I was too early to call this bet. And, my response is the ever lame "i was going to leave when the blinds hit me so I called what I figure'd was my last playable hand"

After the flop I was a bit skittish, not because of the first all in, but because of the call. To this point tonight I had lost two flush over flush's.

Is this an easy call with 1) allready having a flush and 2) having an open ended straight flush?

(also, MP3 debated for a long time and eventually folded. Later said he had QQ with the Q of diamonds).