Almost out of nowhere.

"Are you planning on going home the weekend of the 17th?" he asked.
"Yup!" she replied.
"Okay. I think I should go home that weekend." He didn't say why. But when he thought about it he felt a sudden, unexpected twinge of sadness. Seconds later it was gone.
"Awesome. A ride would be splendid."
"Okay. I'll keep that in mind if I decide to go."
"Okay awesome."
The conversation was over, and he began to talk to another friend. That conversation ended too, not long after. That feeling of sadness came back, only this time it was more than a twinge. Tears began to flow. He put his head down on his desk, cradled in his arms to muffle the sound of his whimpering. He was holding back. It didn't last for long though. It was becoming too much. He wouldn't be able to hold back much longer. He got up, left his apartment, sat in his car, and let go.