HELP with lip ring !?

Ok so I have this retainer but I'm carmel color so the white retainer shows a lot but when I take the top of the retainer off its invisible but I know that without the top it will slide out my mouth.so can I use a bandaid or tape on the inside of my mouth where the flat part of the labret is so it dosent slip out or will it just slide out due to saliva (sp) in my mouth.will tape or bandaid work had any one tried this