Getting confused by the query builder

[twiclo]

This is my code

for v in val {
  dbg!(v);
  separated
    .push_unseparated(format!("insert into {} values (", #l))
    .push_bind_unseparated(id)
    .push_bind(v)
    .push_unseparated("); ");
}

And here's the output

x.sql() = "insert into user_perms values ($1$2); insert into user_perms values ($3, $4); insert into user_perms values ($5, $6); "

I have no idea why the comma isn't getting inserted on the first loop but is on the others