double trouble / double peine

Yeah, I know, cliche, but still... Can you love two persons at the same time? Same kind of love, same feeling? This friend of mine... he thinks he loves two girls. And I asked myself... is that possible? Is it possible to want to be by the side of two different persons at the same moment? Could you just have them both? I mean, look at the Arabians. 4 wives, 1 life, 4 families, 1 kind of love. You can't choose which one to ask about a certain problem. You can't choose who's better in bed, you can't distinct between them, you can't love only one and treat the others the same, only because it's the rule.
How can you possibly feel exactly the same for more than one person in your love life? How can you possibly love them for the same general reasons, if there aren't two identical personalities in the world?
If you were to choose between them, what could be the considerations based on which you would choose? More precisely, COULD you choose? Same feeling, same kind of loving someone, remember!