Lucy is almost 6 months older than Gray and they're pretty much the same size. I think Lucy is a little taller but Gray is chubbier.
One bad thing about having such huge babies is that people expect so much more out of them. Look at them. Lucy rolling around while Gray just lays there and takes it. Most people would think they're the same age and that Gray was a little slow.
This is when it got crazy. Lucy was trying to get to Gray but Mac wasn't having it.
Then both Lucy and Mac teamed up on Gray... I'm sure this won't be the last of the Lucy/Mac tag team. Poor Gray.
Gray survived with only a couple of scratches around his eye. It could have been worse :)