Two BP's in one enclosure good or bad?

[Giddy]

Hi,

I'm new to keeping of BP's and just got my first tank (terrarium) last week. In my enclosure there are two BP's (one F and one M) of aprox. 1 year of age. They have allways been together (according to the previous owner). I've red some thread's on this forum and on the internet, that say that BP's should'nt be kept together in one enclosure and thread's that say that it is not a big no-no if they're young and growing up together.

So, what is your opinion? And if keeping them together in one enclosure is oke, to what size tank should I upgrade when this tank get's to small? My tank measures 40" x 20" x 20".

Thanks for your reply's.