Why are two fish in Pisces chained together?

It was created by KAGAYA (Kagadani Xiang) according to Greek mythology.

The myth of Pisces is that Venus took her beloved son Cupid to a luxurious banquet. When the whole party reached its climax and everyone was intoxicated by delicious food and fragrant drunkenness, suddenly an unexpected guest came. He reached over the food table and threw the potted plants into the pool. His terrible expression frightened everyone present. At this moment, Venus suddenly found Cupid missing. She searched nervously everywhere and finally found Cupid shivering under the piano. Venus couldn't help hugging Cupid in her arms. In order to prevent Cupid from being separated from her again, Venus thought of a way to tie two people's feet together with a rope and then turn them into two fish. In this way, she managed to escape from this terrible party.