My daughter liked her tummy at first but I absolutely refused to take that risk and flipped her to her back if she fell asleep that way. It’s just not worth it.

My older two did when they were little, if you do place him like that to sleep make sure all he has in his crib is a tight fitting sheet. No blankets, pillows, bumpers.

My son used to always want to sleep on his tummy just recently he doesn’t anymore

Both mine slept on their stomachs from day one and they still do