Never

The mantis are strong, cold, ruthless and above all, they never fall in love. This is how a mantis should be, but above all. Only perdition awaits those who dare to break the rules and Orchid knows it very well. So she hates that knight with penetrating gaze and silent presence. She will never forgive him for stealing a victory and her heart.

In this AU, although the vessels do not have gender, they usually feel identified with one gender or another (There are some who never manage to decide whether they want to be male or female). The Knight feels identified with the male gender and the other insects also identify him as a male because of his body language.

The knight in this story is named Hollow

The Hollow knight is called Big

There are Five kingdoms:

Hallownest Hearth (This include City of Tears, Crystal Peak, Resting Lands, Ancient basin and Forgotten Crossroads) ruled by Big.
The Hive ruled by Vespa's daughter
Deepnest ruled by Hornet
Green lands (This include Queen's gardens, Green Path and Fog Canyon) Ruled by Clare, White Lady's daughter
Fungal Wastes ruled by Mantis Lords.
Nobody cares about Dirtmouth.

Full credit to Whisper9