Yes, it's ariocarpus flowering time. I haven't seen any buds yet on my Ariocarpus retusus. Your plants looks like it has a lot of wool at the top, although the beautiful flower is blocking the view of the plant itself. I lost a large A. trigonus several years ago but before it died it produced a single fruit. I have no idea what pollinated it, although I;m guessing it self pollinated, which ariocarpus is not suppose to do. I got a dozen seeds out of the fruit and 10 germinated. So now I have 10 nice A. trigonus seedlings. A. trigonus is odd in the genus in that it usually has yellow flowers. Nice plant Alain.
Normally I gently poke about in the wool this time of year to see if any buds are forming and take a photo but two Ariocarpus flowered and surprised me by being early so I just took a photo of one in flower. It produced another flower a few days after. When I first started growing nobody grew Ariocarpus from seed.