Is this normal for my dad to do?

i'm 16 now and my dad still puts suppositories in me... my mom told me that you do it your self but when i go get them my dad just does it... i'm shy of my dad (he's my step dad but been with him since i was 6 so he's like a real dad) but still it's getting weird now.. it was alright when i was little so is that normal.....