Being on a throw together team it has to be tough. As long as they aren't complaining about your game then just ignore them and bowl. If they are so hell bent on winning they need to "put up or shut up", they help the team out with high handicaps but that doesn't help if they can bowl their own averages.
In this situation I would bowl out the season and hope you find a few people around the alley to jump ship and make a new team. Looks like you may only need 2 people as the other guy seems to bowl well and hopefully has no ties to the couple.
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