sorry, another post within an hour!
We've just moved to USA and want to get DS a bed that has a spare bed for when friends with children stay (like they've damn well promised) so I thought we could get bunk beds which later on DD can have the other (she currently has a cotbed which should take her through til we head home) then my mum says I'd lose bedtime intimacy with DS because he'll want to be on the top bunk and of course it's hard to read stories, cuddle him when he has nightmares/is sick etc 
So been looking a getting a trundle bed (one where the 2nd mattress is hidden underneath) but obviously doesn't have benefit of being 2 full time beds later on..any thoughts?