How can "sitting around" and "talking" come in a row? Is it "present participle"?
Yes, to "sit around talking" is actually a commonly used expression. It is in the present tense in this video, and is used to describe the act of spending a lot of time chatting casually, without doing anything useful or stimulating. The speaker has used this expression to state that instead of wasting time just chatting, they could go outside and actually do something. Ex: It was a relaxing weekend, we just sat around talking for hours. Ex: Don't just sit around talking! Let's go outside.