Explain what the narrator is saying about Utterson’s choice of friends. With what type of people does he enjoy spending time? Why?

From the text:

His friends were those of his own blood or those whom he had known the longest; his affections, like ivy, were the growth of time, they implied no aptness in the object.

Mr. Utterson has a small group of very good friends, with whom has an established, trusting, long-term relationship. He enjoyed the company of his friends because no matter what they were doing..... be it taking a walk or having dinner, there was no need to fill in the spaces with conversation. To enjoy each other's company was enough.