A garment check is when a Mormon looks closely at the outline under your shirts and/or pants to see if you are wearing the LDS ‘holy garments’ or holy underwear. The men’s look like extra long boxer shorts and undershirts, while the women’s only look slightly different. You can google pictures of them online.
If you are wearing them you are recognized as a good, faithful Mormon who has taken certain oaths and learned the secret handshakes to get you into the highest level of Heaven that are taught in the Mormon temple.
Since my husband was wearing an undershirt and his jeans had holes above the knees the clerk was looking to see if she could see the holy underwear through the hole in hubby’s jeans.
Oh, we used to just run up to people and pinch their shirts on the upper arm.
Then say, "garment check!" and run off giggling...
They really hate that....:^p
Thanks for explaining