Be□□n□ □heir□individual su□ce□s, Jessica and K□ystal h□ve also colla□orate□□on vari□u□ pr□jects to□□ther. □rom photoshoots□and □□gazine covers to r□alit□ TV□sho□s a□d cha□ity□event□□□the □ist□rs have pro□□□ th□t they are □ force to be reck□□ed□□ith when they jo□n □orce□.□Their sh□r□d vi□ion □nd mu□ual □□spe□t for each o□her's talents have only strengthe□ed th□ir bond o□e□□the years.