Ok, try this ...
1. Make a Curves adjustment layer. On the RGB channel, select the top end of the curve and move it to an input/output position of 210/255. Then make a midtone point and move it to about 65/130. (This has nothing to do with your green problem, I'm just trying to fix the underexposure in a clumsy way). Press Ok.
2. Make a Hue/Saturation layer. Choose "Greens" and move both the Saturation and Lightness sliders to -100. (At this point a lot of things will look awful, but don't worry about it) Press Ok.
3. Ctrl I to invert the mask from white to black, to hide the Hue/Sat adjustment.
4. Choose your brush tool and make sure your foreground colour is white. Paint over the areas of clothing (her dress and his collar) where the green problem exists. Don't do his face, though.
5. Make a Channel Mixer adjustment layer. On the Red channel, set R+100, G+10, B0. On the Green channel, set R0, G0, B+120. (Again, things will look awful, but ignore it). Press Ok.
6. Ctrl I to invert the mask.
7. Paint with white over the problem areas of his face to fix them.
8. Finally, hold down the Alt key and click on the visibility icon (the eye) of the Background layer a few times, to compare the results.
Let me know how that goes.