He lets them cry.
Just for a while.
Ianto's face buried in his left shoulder, Gwen's in his right, their shuddering bodies warm against his. He hugs them closer to him, his tears leaking into Gwen's messy hair. She looks up at him, all her make-up cried away, her face blotchy and wet. On his left Ianto's hands cling to the fabric of his damp shirt.
"Now we carry on." He says, his voice almost a whisper, biting back tears.
He feels them nod against his chest and he drops a kiss on each of their heads, fingers trailing soothing patterns across their backs.