thought

as punni called ovi in party and punni said loudly that she invited arcana for kelvone only for deal and when ovi said about purvi then punni said loudly that u also told this to purvi and purvi said no !!!! i think thats conversation heard arcana and after that when purvi crying then arcana convince her other way but arcnas face look like she is now protect purvi and arjun purvi dance ,when purvi is upset and purvi saw arcana and also arjun saw arcana and arcans eye to arjun ,looks like arjun and arcan both r know now and arcana assure to arjun that she will manage it ,arcanas eye talking like that way .

if that punni call is nothing then no need to call ovi in the party so i think arcana heard everything and arcana also told to arjun that fact .in precap arjun is scare and he want promise from purvi so i think arju n and arcana get this fact now.