Seeley Booth and Angela Montenegro met on the fifth aniversery of the deaths of their loves and bestfriends. Every other day but that one they stayed far away from eachother and bottled up their feelings, letting them out on that day. What they did had become a sad tradition.
Each year they met at the diner for lunch and then they went and bought flowers on the way to the graveyard, leaving Angela's car at the diner, the owner kept it from being towed. After they arrived at the graveyard, Angela broke down and Booth let silent tears stream down his cheeks. They sat at the graves and talked to them, saying meaningless things about what were going on in their lives.
Booth told Bones about his desk job and how he didn't have any partners to worry about.
Angela told Hodgins about her job sketching people of interest for Metro.
Sometimes Booth smiled when he thought about how meaningless Bones would think this was. When they were done they went to get Thai food from the old place they had frequented and then Booth drove Angela to get her car.
That year Angela's tear lasted longer and the talks were shorter. They were both silent and introspective, more so then usual. They were thinking about how their lives no longer had any meaning to them. Booth never saw Parker anymore, Rebecca had moved away and she had full custody of him. All he had were occasional phone calls with the boy.
The next morning Angela was completely drunk but drove her car to work anyway. She crashed it into a pole and died with a smile on her face. The police never determined if she'd done it one purpose or not.
Booth went to the site where they'd found the bodies five years before. He stood there for a moment before taking out his gun and shooting himself in the head.