(About male models, sexuality, and underwear. Not much language in here — but there is some.)
Not all male models do nude shots, and a fair number who do nevertheless avoid what’s usually called full-frontal nudity (though in fact what’s being avoided is shots with any significant display of the penis, no matter from what angle or viewpoint — what I’ll call dick shots). These models will do nude shots, but only from the rear or with the penis concealed naturally by some other body part. Some models who avoid dick shots nevertheless happily pose for shots in which their dicks are ostentatiously concealed (by a hand or some object) and shots in which they flagrantly display themselves just short of exposing the root of the penis; these are two types of what I’ll call cock tease shots, in which the homoerotic undercurrents of nude male photography are elevated to central aspects of the pictures.
Australian male model Daniel Garofali has made something of a career in cock tease shots (though he does many other sorts of modeling as well), working with photographers who seek out homoerotic content.