We tried board adult board games but found that people either have to much sexual tension and can't concentrate, or they are more interested in continuing a conversation with a couple they have met.
On a 4some couples date, I just sit next to the man and start playing with him. For big parties we make our own games and always begin with a contest. We have a blow job contest and everyone always loves it and participates. What we do is place 2 or 3 chairs next to each other and with blindfolded females sitting, the men line up and for a couple mins the women suck but (Not Touch!) and they men move on to the next. We cycle all the females through the chairs and the men mostly visit everyone. At the end the ladies try and guess the order of men who they gave a blow job to...we have a prize for the winner. It is always a lot of fun and a big hoot when a wife fails to correctly guess her own husband.
And after that we have done something similar to what EuroMex suggested. We play spin the bottle and the two that are hooked up by chance are sent upstairs and they are allowed 5 mins and have to return. It is fun, exciting, and the grins on their faces when they return are priceless. After a few attempts at this, most are ready and headed for the bedrooms and the braver do it down in the living room, kitchen, or dining room.