I suppose it's possible that he thought being a drug mule was just one of the tasks he had to do to woo this woman. Which would be even more boneheaded than just falling for her innocently.
From reading the texts he sent from the airport, and the calculations he scratched out on paper at the same time, it seems that this is actually what he was thinking.
As far as I can tell, he planned to steal the cocaine from Bolivians, fly to Europe with it, and then share the proceeds of selling the cocaine with his new bikini-model Czech wife.