Securing armor pieces

My two armored girls, Asuna and Saber, both have breast plates that would fit together just fine and stay on without a problem until I dressed them in their body suits. Now, the plates like to fall off or not close together all the way.

 

Any suggestions for securing these pieces discreetly? I'd like to take my girls out, but would hate for a part to fall off, especially someplace busy like a convention.

option 1 - change them to an S-bust.

This is what I did to my Saber that one year was crazy enuff to carry her around an anime con in her full armor. The plate around her chest would still occasionally pop, but only on one side, so could catch/fix it quickly each time

 

option 2 - this might be a bit more permanent, but work a thin strip of velcro INSIDE the armor, to keep both halves stuck together

 

option 3 - blatantly tie a piece of string outside the armor keeping it together securely . Color-match to the piece, tie a fancy knot and claim "power-up upgrade" to anyone asking too many questions

S bust....

 

sticky velcro on the inside of the armor pieces... the other side of the velcro stitched to a sacrificial piece of clothing or item that will remain hidden under the armor.