If it is serious, be deliberate, blunt and to the point. Pussyfooting is a pet peeve of mine.
Personally, I prefer to fume or brood in solitude during these times.If you are stressed/upset what is the best way to comfort or reassure you?
If you insist on sticking around, handing me something to break eases the tension.
Back or belly rubs are also preferred (with permission of course).