I had a similar experience when I was younger and made a similar resolve. Unfortunately my spouse considered it very important to produce and maintain this dece

I had a similar experience when I was younger and made a similar resolve. Unfortunately my spouse considered it very important to produce and maintain this deception so I took a hands-off approach and simply didn't engage with the ruse. I put presents under the tree with recepients addressed, but no from field. When the children got old enough to actually ask me directly about it I told them the truth (and got some flak for it from my partner). Fortunately by that time other conversations I'd had with them about dragons, ghosts, and gods allowed them to integrate this knowledge in what I believe to be a pretty healthy way, but I've always felt uneasy about this casual dismissal of children's agency.