Don't understand a sentence

[enaskitis]

Hello! I have a sentence where I'm not sure if I get the meaning of its last part correctly. Here's the sentence:

 

李光头被赵诗人揪者站在那里，看着哭哭啼啼的小屁股，心想你哭什么，你一个没发育的小屁股有什么好哭的，我他妈的是没办法才顺便看了你小屁股一眼。

 

The context is that the 14-year old 李光头 was caught in the public women's toilet peeping at five women's bottoms, and one of the women was a 11-year old girl with a slim bottom that 李光头 didn't appreciate at all; when the women found out they came out yelling at him, and the 11-year old girl was weeping uncontrollably.

Now the part I'm afraid I don't get is the last two segments, which I understand as follows:

 

What are you crying for? You, an unshaped bottom, what do you have to be crying for? Even if I had no other f...ing option I would not throw on your little bottom more than a passing glance.

 

But I'm not sure my reading is correct.

 

One more thing: the text says 你。。。有什么好苦的; could it be 嚎哭的？ Does 好苦的 make sense?

[Carl Chen]

你一个没发育的小屁股有什么好哭的，我他妈的是没办法才顺便看了你小屁股一眼。

 

What are you crying for? You, an unshaped bottom, what do you have to be crying for? Even if I had no other f...ing option I would not throw on your little bottom more than a passing glance.

 

 

趙光頭 indeed glances at the little bottom, but unintentionally. 

 

"The little bottom" think that 趙光頭 looked her butt intentionally, so she cried out loud.

But 趙光頭 regards the little girl as an immature little bottom (趙光頭 by no means watches that girl, in principle)

Unfortunately, 趙光頭 still unintentionally saw it.

[imron]

*李光頭

[Lu]

顺便 'in passing, because I happened to come by there anyway'

I read it as 'I only looked at your little bottom because I couldn't help glancing at it [while my eyes where on their way of looking at larger bottoms].'