How do I control facet borders with ggplot2?

I want to remove the borders along the outer edges of a plot, so only the lines separating each panel remain. Can I accomplish this with theme?

For reference:

library(ggtextparallels) #devtools::install_github("daranzolin/ggtextparallels")
ggtextparallel(parallel_no = 25, version = "eng-ESV", words_per_row = 6)
ggplot(data=tibble(f=1:3,x=1)) + 
 geom_blank(aes(x,x)) + 
 facet_wrap(~f) +
 geom_vline(data=tibble(f=2, x=c(-1,1)*Inf), aes(xintercept=x), col="red") +
 theme_bw() +
 theme(panel.border = element_blank(), 
       panel.background = element_blank(), 
       panel.grid = element_blank(), 
       panel.spacing.x = unit(0,"line")) 

Thanks Baptiste! You're a legend.