You should just ping him.
Better yet, get your cousin's phone number and give him a call this summer when he's done studying.
Ping him?
I dunno. They're supposed to make two yearly weekend visit every summer and Christmas. Justin didn't come to either last year for various reasons. I heard he felt terrible about not being able to come, though.
So far, I haven't heard any news on when they'll be coming up this year ("they" being my Aunt, Uncle, and Grandmother. And cousin, if he should come).