I agree with some of the posts below about your bra being too big. When I bought my forms, I had a sports bra and a regular bra that I tried to use them in. They worked great with my ‘rice in stockings’ forms, but my actual forms moved around way too much. (I can’t adhere them because of chest hair.)
I have a 41″ chest at the nipple (without forms) and 38″ 2″ below. I used the table on the sponsors website and that guided me to be the appropriate bra (see the link below). I bought 1200g teardrop forms and bought the Amoena pocket bra (42D). It fits PERFECTLY and fits the forms perfectly. When I have it on, I truly have my own breasts! They bounce and jiggle, but are anchored to my chest in the pockets. And the bra is VERY comfortable!
*kisses* tara 🙂