do I need 15 denier synthetic yarn to fix a hole on a 15 denier hold up?

My 15 denier hold ups have a hole I want to stitch (15 denier is considered very thin). All I have at home is your regular 100% cotton yarn, no idea what denier.

Hole is on a toe, so nobody would see it if I don't wear sandals. Am I going to ruin them?