I know your office...its that place that located way back in the 1950's.
eughhhhhh
I would NEVER make ANYONE a cup of tea as a duty. I would only ever make one for someone else if they make me one and we all just kinda make them for each other when in the kitchen.
I really couldnt stand the idea that someone see's it as their duty to feed and water me.
Go in early tomorrow and make your new Junior a cup of tea , then bask in the self satisfaction that you have repayed your debt
Thankfully, further North than you, we dont see making someone a cup of tea as a big deal.