Movie made 2010 onwards. Small release movie. Lead actress has Scottish accent. Red hair. She plays a prostitute who wears a link chain around her body and likes to be mistreated by her clients. She meet a naive woman at the beach and the befriend each other. This woman accompanies her to meet one of her clients. Seeing how she is being mistreated, she strikes the man and the pair end up killing him. Realising that things have gone too far, the prostitute asks the naive woman to drown her in the beach where they met.
British Movie: two girls meet at the seaside, one is a prostitute who gets drowned in the end
Butterfly Kiss? Butterfly Kiss (1995) - IMDb