Here's why:
* Bernie and Ben are two people, making them plural.
* They is the plural pronoun that refers to two or more people.
So the sentence could be rewritten as: "They went orienteering with scouts."
Here's why:
* Bernie and Ben are two people, making them plural.
* They is the plural pronoun that refers to two or more people.
So the sentence could be rewritten as: "They went orienteering with scouts."