This post will be on the Stay Flawless 15-hour Primer from Benefit. I did a quick mention of this in a post a short while ago when I reviewed the Hello Flawless Oxygen Wow Foundation by Benefit saying that I was liking it so far but wanted to use it a few more times before I did a full review, so used it for another full week before writing this! I like to use a product a lot/for a long time before doing a full review as I feel that sometimes it can take a while of using the product, getting used to the product, and finding the best way it works…