Hysterical to participate in, watch others, & actually hard to do! Babies put a lot of effort into sucking.
Fill clean, matching baby bottles 1/2 full with water. Close with the ring & nipple. Check to make sure there is a hole in the nipple. Each person at the party gets a bottle. The first to finish gets a prize. It's funny to watch ladies who don't want to mess up their lipstick too!
You can also divide the rooms into teams (maybe 5 members on a team) & everyone on the team must finish for that team to win. To make it interesting, still have a prize for the overall single winner of who finishes first too.