Dennis stood there in the little 'bubble' she'd created and he just felt confused. Scream? Yell? He opened his mouth, but nothing came out. He was bottled up so tightly he couldn't let anything out. So he stood there, trembling, looking around almost desperately, as if he expected the bubble to pop if he waited long enough.
The longer he stood there the more discouraged he felt. He wanted to let it out but nothing was happening...
and then, finally, he collapsed.
Something just snapped, something let go, and he dropped to the ground, and he sobbed.
There was no screaming, no yelling, no cussing, just quiet sobbing.
And if he hadn't been so consumed by grief he might have been worried that while the bubble stopped people from hearing if anyone walked by they'd see and sound or not it'd be clear what he was doing.