Yes. And that's okay. It's a (AAAH DON'T SAY IT) penis. Inappropriate? God no. All dudes have 'em you know. Same as all women have breasts (well, I guess males have breasts too, but you know what I mean lol) Male and female genitalia is part of our human anatomy. You can't say it's "inappropriate" to see or have something that every member of a single population has.
If you ever decide to take classes, you'll see that it's a very sterile environment. They aren't standing around playing with themselves or anything, it is nothing sexual like people imagine it to be. In fact, depending on where you go, you might find some really awesome models, some who are willing to actually sit and have a conversation about you while they pose, about everything from world news to last night's soccer game to video games. I know I have one life drawing model who we talk to all the time about games and stuff :U
So it's not as bad as you think. Although if you aren't a certain age, they might not let you in u o u (some places require you to be 18+, it just depends what their rules and code of conduct is).
And if you draw the males without their junk, they'll just get angry at you for drawing them like Ken dolls lol 