My sister is only sisters that knows sign language and sometimes we would tell things front of hearing people while they just look at us signing. Not knowing a thing. We would laugh or whatever together and the hearing people look at us nut then look away and do their thing. Pay Back, Huh?
Now we both are mother of 1 daughter each and we tell things about our daughter. Its awesome relationship that we have because we can talk either speaking or signing. 
My other sisters are used with voice and that goes with my mom. Tomorrow easter I know I will be left out so I'm just gonna be real busy with my daughter or bug somebody. 