Well, Rydia IS slutty enough to wear something like that and go pick up guys, but… really? This dojin is too short to make any sense, and the translation is terrible to boot. Sentences like "Your hands are already in the bed" read like the result of a machine translation, and there are typos scattered throughout (such as "Excnage", "Ofcourse").
At least we got a serviceable look at Rosa's ass on page 7.
Edit: @ArshesAsh, it was implied the same place Cecil x Rydia was. Also her FF4TA design.