so what if i submitted both xml sitemap and submitted another sitemap (for videos for example) in robots.txt? are both of them gonna be indexed? or one will override the other? here's exactly my confusion...

i actually have my sitemap in the root of my site, and i am in process now for making my content rich by adding videos and implement video SEO for it, so the video seo tool is advising to add 1 line to robots.txt to point to the sitemap that is hosted on their servers for videos, i am not sure what to do now.. i wish if i have separate sitemaps, but not to index them in one file, i want to keep the default way for videos to be added to robots and leave my other sitemap as it is, how could i perform that?