Sitting up question

Taylor

Okay, I think my son has completely skipped sitting up. He recently learned how to crawl so now whenever I try to get his sitting up time in (he’s surrounded by pillows), he just lunges forward and crawls away. I am wanting to start BLW, and I have given him foods in the past and he didn’t seem like he was straining to sit. I’m just at a loss, he is going to fast and doesn’t want to stay in one place anymore. Help!!