def flatten_html(html, *remove_tags):
    copy = html

    for name in remove_tags:
        while True:
            soup = BeautifulSoup(copy, 'html.parser')
            tag = soup.find(name)

            if not tag:
                break

            parent = tag.parent
            children = tag.contents
            index = parent.contents.index(tag)
            parent.contents[index:index] = children
            parent.contents.remove(tag)
            copy = soup.prettify()

    return copy