Dad: separated, divorce almost final; good relationship with ex - no bitter fighting.
3 kids, 22, 19, 17. He is living with his girlfriend, youngest daughter living with Mom.
Girlfriend: Never been married (almost, a couple of times); no kids.
Problem: Ex going on trip over weekend, asked Dad to stay at house with 17 year old (overnight), so daughter can watch the dogs, go to work.
GF having a cow. Dad doesn't see what the big deal is.