Why is my son sleep like this

My son sleeps with his head shoved in my armpit no matter if I’m standing sitting or laying down when it’s time to sleep or take a nap he will shove his head into my armpit or cry until he’s in there I’m worried that he doesn’t breathe well but it’s the only way to get him to sleep. I thought it was because he could be hungry but even after feeding him he still does it and I thought it was because he likes how dark it is but even in the middle of the night in complete darkness this is what he wants