This product is waterproof, which is very handy during summer.
From Amazon
Diego Dalla Palma MakeupStudio Stay On Me Lip Liner Waterproof - 45 Candy For Women 0.04 oz Lip Liner
Notino
Diego dalla Palma Stay On Me Lip Liner Long Lasting Water Resistant waterproof lip liner shade 45 Corallo 1,2 g