She drove him from Dublin to his house (initially offered to bring him to Thurles)
To be fair he was;
Hungover (hangovers make me very lazy I get grabbing a lift over public transport)
Stoodup (he thought she felt sorry for him)
He had been introduced to her as a friend of a girl he thought he was starting a relationship with.
Also, it is different for guys, as a girl I would be terrified to go into a random lads house to meet him for the first time, and also would never get into a car with a man I didn't know. It's not right or fair but I feel women, in general, would be far less likely to be as trusting and take as many risks.