The belt concept was exactly what I was looking for, but even the narrower end of the buckle didn't go through the belt loops on any of my pants.
Nylon Salmon Belts with Steel Buckle
51 Review
Tipsy Elves Santa Spinner Festivities Men's Accessories for Belts
58 Review
Optimized Classic Leather Ratchet Click Men's Accessories and Belts
50 Review
Spec Ops Brand 100150101 Better Regular Men's Accessories
40 Metal Collar Stays Box
9 Review
220 Plastic π Collar Stays for Organized Closet
π§² Wurkin Stiffs Plastic Magnetic Men's Accessories and Collar Stays for Stiff N Stay
8 Review
π Revolutionize Your Style with Fashion Anchor Pack Collar Stays