When you're young, you are fascinated by s. You actually see them grow on girls at school before your eyes. One year Betty is flat, the next, she's bouncing all over the place. There they are, right under her face. You want to touch and squeeze them. It's all you think about sometimes. You finally get a feel, maybe over, maybe under. She lets you get under the bra and squeeze. Her nipple gets hard. You your pants. It's like magic. That's all you need.
Then you get older. You've seen a whole lot of s, if you're lucky. They lose their luster. They're still nice, but they are part of the overall package now. Besides, it's all about the pussy. You just want to live in that thing. s are just something to look at while your ing. You start to long for that special feeling you had when you were young and there were s sprouting everywhere.
That's when it happens... You start to notice that the asses are getting bigger. They were bouncing right there in front of you the whole time. How could you not notice? You want to touch them and squeeze them. It's all you think about sometimes. Your focus during sex begins to change. You are... all about dat ass.
So, to answer the question, both are great. However, I would never again date a woman with a skinny ass.