[wideawake]

Is the guy behind the limp-wristed guy with the phallus in his mouth wearing a Yankees hat and a Mets shirt?

[1rudeboy]

Note the catcher's home jersey:

[tanknetter]

Is the guy behind the limp-wristed guy with the phallus in his mouth wearing a Yankees hat and a Mets shirt?

On the Mets shirt, the one letter on the second line that's clearly visible is a "C". To the left of it is a straight line, which could be a "U".

I'd conclude that the shirt fully reads: "METS SUCK".