Rinaldi, the surgeon at the Red Cross Hospital, is important to the novel not only because he gets some really great lines, but also because he is of ambiguous sexual orientation. He sleeps with female prostitutes, but he expresses a desire to kiss Frederic several times. Is he a very affectionate straight man? Is he gay? Is he bisexual? All of these interpretations are possible. A Farewell to Arms shows us, in part through the character of Rinaldi, that masculinity comes in all shapes, sizes, and flavors. Frederic’s friendship with him also refutes claims that Frederic is just a crude, macho guy. If he was only that, he may have socked Rinaldi in the mouth all those times when Rinaldi was putting the moves on him.