How do I pose brothers?

I am photographing 4 brothers this evening (VERY last minute shoot), ages: 14, 15, 19 and 20. I have absolutely NO idea how to pose them.
Their mother seems to want more classical poses, but I have no idea what a "classical" pose is, for brothers! (I was expecting this to be a family shoot - and they changed it on me)

would like to see some of these when you are done. Did a four brother session last year and was not looking forward to it. It ended up being pretty easy as the guys ended up being pretty good at doing their own thing for the camera. I just found different locations and told them to jump in and do whatever. As they were doing "whatever" I would then slightly change up what they were doing. I found it easier to modify their look instead of creating it for them. These were definitely not "classical" photos though.

I'd say, look up groomsmen photos from weddings and emulate those for classical poses. though this message is a day to late.

Just watch a Tarantino movie. Tons of classic poses for boys there