2002 Honda Civic: Starts in the morning, but wont start after driving for a while?

I have a 2002 Honda Civic. I have been having a starting issue with it for some time now. Let me give you one of the common senarios:

I use the car in the morning to go to the beach with some friends. The car starts and runs just fine. I pick up my friends and we go to the beach for about 2 hours. We get back to the car and it starts fine. Then we get to Chipotle to eat lunch. We eat for about 30 min and then go back to the car. The car does not start. When the key is turned, everything sounds good, dash lights up, and the engine turns. However, it does not start. I wait 10 minutes, still nothing. I decide to walk with my friends to the next destination and leave the car sitting for 2 hours. I get a ride back to the car from another friend and it starts….

So, long story short, it seems like the car will only start properly after it has been sitting for a few hours (there are other common stories with this car). I tried one of the relays in the glove box, but that did not fix the problem.

What do you think is the problem???