Hasebe's indeed a genius, tricking Chihaya that easily. But I guess that also means Chihaya's distaste of Hasebe's intentions isn't really that deep. Or rather her interest in cosplay and dressing up Lucy is all the more deeper in any case. As opposed to that, it looks like with Tanaka fists do the talking far better than any genius lines would.

It's getting pretty comedic to watch Lucy refusing a romance yet she's still in fact actively making Hasebe like her all the more.