Ok so I found out what 'genuflect' means, so why it is done in marriage proposals and other non-religious circumstances?
Genflexion is a latin phrase for bending the knee or getting.
Catholics traditionally do it with the *right* knee specifically. Could peeve off the catholificated crowd by using the left knee. 8-)
"Genuflect refers to the act of bending one knee (usually the right) to the ground, serving as a gesture of deep respect, worship, or adoration, primarily within Christian traditions like Catholicism. It symbolizes humility, submission to God, or recognition of the Eucharist. It can also mean being subservient. "