Is Billie a grandpa now?

At the Fillmore show Billie was wearing a tshirt that said "Gramps" in a font similar to the band Cramps, but there's no band or album by that name, so I think it refers to him becoming a grandfather. What do you think?

At the Fillmore show Billie was wearing a tshirt that said "Gramps" in a font similar to the band Cramps, but there's no band or album by that name, so I think it refers to him becoming a grandfather. What do you think?