Splitting costs on joint trips

When a person joins a couple on a trip and shares their room to save on expenses, how do you split the cost of the hotel room? in half or thirds?

Thirds. A couple is still two people; they use two people's-worth of time in the bathroom.You can do it in halves if you - the third wheel - are feeling benevolent but a couple should never demand such consideration.

I think it would depend on who invited whom, and perhaps even how the plans were made. Did all three participate in the plans, making sure that each would be able to take time off at the same time? If so, IMO the tab should be split 3 ways. Also, if the third party invited the other two to join him or her on the trip I would say split it 3 ways.But if the third party suddenly discovered that the couple was taking a trip at the same time and to the same place that he or she had independently planned to take alone and offers to ride along and share a room, in my opinion the third party should offer to pay for half the room. That's what I would do, but I would expect to split the other travel expenses three ways.If this last scenario is what actually happened (and this exact situation has happened to me), I do hope that the third party made CERTAIN that the couple wanted him or her along for the trip.

---

"I think younger workers first of all, younger workers have been promised benefits the government promises that have been promised, benefits that we can't keep. That's just the way it is." George W. Bush, May 4, 2005