Love dart is apparently not as romantic as is sounds. You can read more about this in these two articles:

The love-darts of land snails: integrating physiology, morphology and behaviour

By Monica Lodi, and Joris M. Koene

A Syringe-Like Love Dart Injects Male Accessory Gland Products in a Tropical Hermaphrodite

By Joris M. Koene, Thor-Seng Liew, Kora Montagne-Wajer,  and Menno Schilthuizen

(Last accessed 16.03.2021)