This is a pile of sleeves, as I am not wearing any in the month of July, and now, neither is Dave. I have a similar pile at home, and now also, so does Dave.
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We're going to hang on to them, in case we want to sew them back on in the fall.
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The neck slit is optional, but de-sleeving is mandatory, after all, it's July.
It may be The Rule of August as well, we'll see.