To get excited we dress in something interesting. Think of sheer back-seamed stockings, shiny pantyhose, tight swimsuits or leotards, latex catsuits, high heels, you named it. (Not many males consider such things “normal” clothes, that do not pump blood into the proper places). But then we add chastity devices, tightly bind ourselves (or someone put you in an inescapable bondage, if you are lucky), to prevent masturbation.
Hm… Yes, OK, sounds logical…