I'd say no harm no foul. If you had taken his money maybe he'd be pissed at you the rest of the trip and that would suck. Also if you make it known you two know each other I don't see a big deal in that as well. GF/BF's sitting next to each other usually advertise this and it's not that big a deal. usually one is way worse than the other and that'll iron out any "teaming" up issues.