Fukiyose would slam the phone shut without a word, he's even less likely to call and involve her in something danger related.
Plus maybe the bra in question is a SMALL one, and kamijou's man brain assumes small ones are different!
As for Saten... Sumeragi-san, are you implying that Saten and kamijou has exchanged phone numbers from only after 1-2 meetings when it took so many volumes from misaka
?