Well, my T is a campus T. So we see each other on campus off and on.
I was involved in a project that she is an advisor for.
(This is how I found out:

le me: *late for meeting* Craaaaap. This is not the best way to start a first meeting!
*walks in door, expecting other students and faculty members*
Me: *smile* Sorry I'm late guys, was too busy watching my plan to take over the world.. not work.
Everyone: Hey dis! It's ok...
*looks at room and notices T*
Me: Oh dear. Hey everyone.
Chairperson: Right, this is Dr.____. She'll be part of the committee. You'll work with her on x, y and z.
T: *smiles* Small world.
Me: Small campus. -_-