Sharon Astyk offers a dozen reasons why couples might prefer to stay married during tough times, rather than divorce. Here are a few to whet your appetite.
2. You can't afford dinner and a movie, much less romantic gifts for your mistress or new sweetie anyway. You might as well stay with someone whose expectations have already been lowered by exposure to the real you.
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6. Newly met potential partners are often turned off by birth control discussions that require low budget home vasectomies or or craft-your-own condoms.
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8. Huddling together for warmth with a damp spouse who has just come out of the barn is marginally more pleasant than huddling with a damp dog who has just come from the same place. Usually.
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11. Spouses/partners who truly love you, may come to find your true hair color/hairy legs (face? back?)/chronic allergic snoring/tendency towards simultaneous wrinkles and zits endearing after you can no longer locate or afford products intended to conceal them. One hopes.
There are more at the link. Very funny and recommended reading.