Why was Two-Bit relieved when Ponyboy picked up the broken glass?

In the book "The Outsiders" there are a group of boys that call themselves Greasers.  They are the social outcasts.  They get into trouble and represent the typical gang ideals of the 1950's.  They are from a low income neighborhood and don't have much going.  Pony Boy is different.  He tries to be like all the others an he is in most ways.  However, he has academic abilities.

Two-Bit is one of the boys friends and a member of the gang.  He sees that Pony Boy is determined to be a greaser just like he and the rest of the gang.  However, he is relieved when Pony Boy cleans up the glass, because it demonstrates that he has a different nature than the rest of the Greasers. Pony Boy doesn't want anyone to get hurt on the glass.