From ESPN:
Boston University and Holy Cross will both wear masks for Tuesday's men's college basketball game, a Boston University spokesperson told ESPN.
The game is believed to be the first in men's college basketball this season in which both teams will be wearing masks on the court.
Stadium reported Monday morning that Boston University has mandated that all of its opponents wear masks during games on BU's campus. The Terriers and Holy Cross also play each other on Monday, but that game is on Holy Cross' campus, meaning only BU will be wearing masks during the game.
Edit to add: Masked wearing Boston College beat unmasked Holy Cross today (Monday).