It's wrong to ruin other peoples good time.
Billy is not having a particularly good time with his friend Robin while they are at another friend's house.
Billy wants to do something else.
Billy tells Robin that he is going to go out and get some food to bring back to get some fresh air.
Billy tells Robin that he wants to leave, that he's not having any fun at all.
Robin is happy Billy is getting some fresh air while she can see he needs it.
Robin gets upset that her friend isn't enjoying himself.