User blog comment:B214/Question and Answers/@comment-173.25.192.134-20131021021246/@comment-1392308-20131021230040

Xenovia has been a "victim" of Dress Break from one of Issei's clones in Issei 300. Azazel created Issei clones (against Issei's will) which had the perverted natured maximized which caused them to run around the school stripping every girl in sight. Xenovia was one of them.

Irina has never been stripped by Issei though. He has seen her naked though in the short story, Lets Go to Onsen.