What happens to rib muscles and the diaphragm when you
inhale and hold your breath?

When you breathe in, or inhale, your diaphragm contracts and moves downward. This increases the space in your chest cavity, and your lungs expand into it. The muscles between your ribs also help enlarge the chest cavity. They contract to pull your rib cage both upward and outward when you inhale.

Explanation:

people are just afraid of difference. honestly no where in the bible does it say you can't be gay or bi or anything it says he loves all his children the same and he wants the best for us but we need to be truthful and all that yadda yadda anyways, god doesn't hate gays, he does hate hate, hypocrites, liars, and all that and even then he forgives those who ask for it. so your mum's reasoning is totally wrong xd sorry love, i had to rant a bit but i hate it when people do that. if anything i accept you! stay amazing! ^-^

depends where it is? i got mine on my arm and from 1-10 it was a 3 different spots react differently