learning to sit up

Kasi • Mommy to Killian Lee Gonzales (12.29.16) pregnant with my second due 07.27.19
I'm trying to teach my 5 month old son to sit up on his own. But he's so determined to stand. He always wants to be on his feet while we hold him. I'll sit him on his butt and he'll push on is feet so he'll end up standing. He also throws himself back which makes it hard for me to let him go so I can see how long he can hold himself up.