Maybe he's like me and never offers because he doesn't know where anything is in the kitchen! (I only ever drink water, no hot drinks) - Oh, but I also never ask for a drink when someone is getting the drinks in.
Do as someone I work with did, make a program thats basically a random number generator with everyone's name to dish out, then rig it so if you double-click the button it always comes up with his name. Should give you a couple of days of tea.