There are a few things you can do to catch someone cheating on Instagram. First, make sure to check your account regularly to make sure that your posts are up-to-date. If you notice that someone is not following theirInstagram account as they should be, it is possible that they may be cheating on their account. Additionally, if you see someone posting pictures of themselves with other people without their permission, it is possible that they are cheating on Instagram. Finally, if you have suspicions that someone is cheating on Instagram, reach out to them and ask them to stop. This will help ensure that your account remains clean and accurate.