Ally with those you hate

I've just been playing a game as Egypt, and venice offered me an alliance, which I accepted, just to keep them off my back while I trashed the Turks and then Byzantines. But I noticed the AI then had HRE, Milan and Sicily smack up the Venetians, which up until they allied with me had been doing very well. That suited me fine. So maybe in future I'll always ally with people I hate - like as England ally with France, knowing this means they AI will then tear them apart. Anyone else notice this going on?

I think that's just the standard Venice-bashing which has become standard post-patch... They either seem to be destroyed, or take over italy, balkan, austria and switzerland...

Actually I'm playing pre-patch, so I'm not sure how standard the Venice-bashing is. But as the AI expects you to ally with non-adjacent countries to attack adjacent nations from the rear, it seems it won't expect you to mess around with its program.