Embroidering a brassiere with polyurethane inner. Will I damage the garment or its materials if I sew into the polyurethane?

Update: Hello, I'm new to the art/craft of embroidering. I have a project embroidering a brassiere. I'm doing this by hand using plastic sequins and beads. I'm hesitant to sew on sequins/beads to the very thin Outer (91% cotton, 9% elastane). Can I sew part way into the Interior padding (100% polyurethane)?... show more Hello, I'm new to the art/craft of embroidering.

I have a project embroidering a brassiere. I'm doing this by hand using plastic sequins and beads. I'm hesitant to sew on sequins/beads to the very thin Outer (91% cotton, 9% elastane). Can I sew part way into the Interior padding (100% polyurethane)? Will that end up damaging the garment?
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