You dared him to play love and deepspace.

"Wow... Xavier's handsome." He interacts with him as his mc and Xavier get intimate. "Oh are they gonna do it? Oh they are definitely gonna do it!" Xavier gives his mc neck kisses "OHHHH!" flustered Tanjiro noises. "I can't look at him... he's too handsome-"

You can tell that he's a Xavier fanboy.