QGD/Slav + 2.c5 .... ?

As black, i think e5 is best, if 4. dxe5 then Bxc5 ...... if they dont take it gets ugly, anyone have any suggestions? 

P.S.: Sorry the title is wrong, its supposed to be a 3.c5

Well, I know its a bad move because NO master has EVER played it according to game explorer.  I just won a game against it too, but if I dont take that pawn out quick it can be awfully annoying - it almost eliminates the dark bishop!

My main concern is whether I should try to get that off the board quick or just let it stay, develop around it, and pick it off later.

I've thought about this before, and I think that ...b6 is best. It actually undermines the white pawns, because white cannot maintain the tension. Against ...e5 white just plays e3, and black still has to do something about that c5 pawn. Why not just play ...b6 right away, since you'll have to do it eventually? And if you give white some consolidation moves, for example if black just plays Nf6, Bf5, e6, Be7, o-o, etc. then white will eventually be able to answer ...b6 with b4 and could get an advantage.

Thanks for your replies guys!  But ozzie, if you play b6 immediately do you take with queen or pawn?  I remember i took with pawn one time and i ended up paying for it because of the immensely weak e6 pawn - but that may have been an entirely seperate blunder

@dd1123 I think you mean the immensely weak c6 pawn, and here's the thing about that pawn structure. You can easily play ,..c5 and liquidate the c6 pawn weakness, but then you have the b5 square weak. I think I take with the queen.

cool, I appreciate it so much ozzie and anthony.