Sexy shrimp fighting over possible mate?

[keringabriel]

Hi everyone, I've had sexy shrimp for almost a year now and every time I see to purchase around 5, I end up with three no matter what a few months later. I tried to remove anything that might possibly be killing them however I've never seen aggression displayed from my clowns towards it nor have my cleaner and peppermint shrimp attacked it that I've seen. I've since theorized after watching the video above that perhaps maybe the males sexies killed each other while attempting to gain the attention of the female? Idk what are your thoughts?

Update: my tank is 20 gallons and it's residents are

2 clownfish
3 peppermint shrimp
1 skunk cleaner shrimp
1 high fin goby/pistol shrimp
2 sea urchins
1 Pom Pom crabs
1 porcelain crabs

 

[Rocks reef]

You are correct in your assumptions. Males will kill one another when courting, also cleaner shrimp will kill sexy shrimp at times.