My son is like me - he doesn't have good posture and he vastly prefers to to lie down versus sitting up straight. He will lie down on the couch, lie down on the floor... he just loves to be horizontal. I encourage him to sit up as much as possible (especially during the day), but it is very much an uphill battle.

My daughter has incredible posture (no idea where it came from), and likes to sit with her legs crossed and her back straight. She can hold that position for hours - which is amazing to me because I have terrible posture.

Does your LO have good posture? And just out of curiosity, does anyone have an LO who loves to lie down everywhere?