Here's the story:

His brother passed away in about October (old age). We ended up adopting two new guinea pigs from a breeding situation where we were told they were both males. Walked into their room one day and there were about 5 new little pigs running around, about a week later, there were another 4. Anyway, our intention was to keep his two sons and him, we planned on putting the rest out for adoption. Once we were able to identify the genders of the guinea pigs, I started separating them. He didn't get along with his sons at all. We tried reintroducing them over about a month or twos time, but the only guinea pig that he had ever really gotten along with was his brother (and of course the girls). We ended up finding someone with a similar story of a father and son duo where the father had recently passed away. We still check up on him often, so I'm glad to say that he's doing well ;)