I think you meant "Sirena Sirens" or more likely "Siren Sisters" or even "Mermaid Sirens" but I'll assume you are referring to "Siren" in mythology and popular culture similar to the "mermaids" often referred to, and create content related to mythological creatures known as Sirens or "mermaids" similar to;

In the meantime, here’s a general framework you can use (or that I can flesh out for you once you provide more details) to assess any product or brand:

"Sirena" is a popular makeup and beauty brand, and "Ersties" is a well-known adult entertainment platform featuring amateur performers. The combination "Sirena Ersties" refers to a specific model or performer named who appears on the Ersties platform.