At what point does a guy in a ladies cardigan become obvious?

I always think stealth crossdressing is the most interesting, a dress or skirt is going to be noticed. However cardigans, blouses, tops can be worn & may or may not be noticed depending on colours, textures, what it's worn with, etc. As cardies are my thing I focus on necklines, buttons, softness, colours, patterns, cables, belts, etc., etc.

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