1. They smile &/or laugh. Say that's OK. Comment on how adorable my children are & start a 3.5 minute conversation about their own children.
2. Might smile or give "the look." Possibly say excuse me or "that's alright."
3. Grunt or completely ignore the irritation. They give me a serious "look" even when it was their own fault & they should have said excuse me instead of myself or my kids.
Maybe I can get paid for this type of research...............