Playing Xbox 360 Games On Two Consoles?

So ima make this quick since they destroyed Horizon and I have nowhere to ask this question without a reliable community to answer my questions.
Anyways. It’s quite confusing what I’m about to ask but it goes along the lines of. If I buy a 360 digitally and play it on the xbox one can I still play other games on the 360 while play the other 360 on the xbox one.
I’ll try to simplify if for those who can’t understand.

Say I let my friend use my account for the 360 and he plays minecraft or Cod.
And I wanna play Left 4 Dead 2 on the xbox one.
Would he not be able to play any 360 games while I’m on the xbox one playing left 4 dead 2?
Couldn’t have worded it any better. Hope you guys can understand it.

Well…I thought this was an active community.
Guess it died. Pity.

Sooooo…that’s a yes I can play Left 4 dead 2 while he plays something else one the 360 while I’m playing it on the xbox one?
And bro my jets are going full blast right now lol as soon as I get off work I was gonna go buy it.
Didn’t wanna buy the game if it would kick my buddy off.
So it was either gonna be left 4 dead 2 or just pre order BattleBorn. Lol

Well f*ck.
Thanks " brotato chip"