We've had them a month now and they've been good (they are a year old, from a rescue)
A couple of times GP1 has given his smaller bro a head-butt or a warning noise.
Outside they have plenty of room 5'5" x 5'5" with a big hayfilled box and three other little 'houses' plus a ramp and platform too get ontop of the wooden box.
GP1 tends to go in the cardboard box within the wooden box which has a fleece. GP2 tends to like behind the box up to his ears in hay (deep filled)
It's cleaned out and the hay, lining and fleece changed daily. The rest of it every other day.
BUT the inside cage is understandably smaller, 4'x2' x 18" high.
By the time a box is in,water,food,veg and hay, there's not alot of space.
Last night after their cuddles, GP2 went for his brother. I don't know if he got him,we can't find any scabby areas and he was fine to cuddle today. But he got his mouth onto GP1 s back, about 4 times.
We seperated them into a washing basket (for GP2) and the cage, then after 30 mins, let GP2 back in.
They spent the night at opposite ends of the cage, no more heard.
Today I put them out, and they are sleeping outside. There was a "Shift yourself" "Bugger off" exchange as GP2 went into GP1s box, but that was it, they found their supper next.
So, my dilemma: if they stay out all winter, I'm quite happy to carry on with fleece, loads of hay, Snugglepad in the box, hot water bottle (in a fleece cover) in the hay.Hope this would be enough to keep them snug. (They are big lads BTW )
DH has put a divider in the indoor cage, so they can still see/smell each other
but they would only have room for hay and veg. They wouldn't need pellets at night and they don't touch the water.
There are going to be some nights when I wouldn't be happy going to bed with them outside.
They had eaten loads of parsley and coriander yesterday.Maybe that contributed to their arsey-ness? (No herbs today, little blighters) 
Any thoghts? (These are my first boy pair)