Why is my butt SO bony? Any ways to make it bigger?

I'm 20 and male. Women tend to carry more weight in their buttocks and thighs, but we men usually don't. Plus, I'm white, lol. If you've ever watched King of the Hill, and saw the episode where Hank Hill went to the doctor and was told he "has no @$$," that's how I feel, lol. Just like Hank Hill.

I've always been naturally thicker, but not in my butt. I was pretty pudgy as a kid. I ran around a lot and ate healthy, but I was still kind of fat - overweight, but not obese. In middle school I tried desperately to get rid of my gut. I did lots of sports too. It was really tough, but by high school, I was 5'6" and 125-130 with cut muscle and definition. But I still had a little pudge on my lower belly that just REFUSED to go away. I decided it wasn't worth it, and kept working out, but not as much, and still did sports. I went back to a more normal, less obsessive diet. The weight piled on of course, and in my late teens, I settled at 5'7" or so and 170. I'm wondering if that's just my body's natural shape. I think I have a predisposition to be a little stockier, and when I was skinny in my mid teens, it just didn't look right on me and was really tough to get. I still eat healthy and workout. I've accepted my body type.

But, as with most guys, the weight goes to my belly. I have a belly, not a huge one, but it's there, and my arms are fairly muscular. My chest is big and solid. My legs have always been thick for a guy. Lots of muscle in my calves, and my thighs are really big for a guy. Muscle, and some fat.

But my butt is just nothing. As much as I've worked out over the years, lower body work outs never really did much for it. I have just a little muscle down there, and basically no fat. My lower back, spine, and butt bones get really sore when I sit. I need more padding down there! Plus, I'd like to actually have a butt.

Sorry for getting off topic, but I always find it attractive when girls have big fat "ghetto booty," lol. Of course, that wouldn't look right on a guy, but I wish I had SOMETHING. I'd imagine they sit quite comfortably, lol.

I just want something down there. Some muscle, some fat, whatever. How can I gear some weight there? All my lower body workouts helped my thighs and calves, but my butt is just non-existent. Any ways of changing that short of injections or surgery?

Thanks!