Proper BDSM requires an actual fit on the equipment. Loose or Too Tight equipment will just cause problems over all in the play.
Now, I am sure Author-sensei did not really think of this when this scene was made and just wanted to have an excuse to make a BDSM section cuz it looks good.
However, actually doing it right would require proper measurements so things stay snug and sexy... this is where Imouto-chan could get good measurements.
Cultured knowledge.
Anywho, I'm sure that people were ran through with the shock that Gorilla-kun was actually Gorilla-chan (I hate myself that I thought of Misono Mika-chan when this got revealed...).
It is also quite a shock that, when people activated "pattern recognition", MC will most likely have another capture target right there.
Now, it would be indeed interesting to see a Muscle Mommy body-type harem member for this one. However, considering that all of MC's Harem is a blend of "sexy" "cute" and "beautiful", she will definitely be softened up massively once the "curse" is lifted.
Humu Humu.
Or it could be like that one Manga when the Horse they were using to pull their carriage becomes a sexy/beautiful girl when the full moon is out and the MC unknowingly f-ckers her and only found out later on who she was.
Anything is possible in Anime and Manga, dear friends!