You can but it may significantly slow down your computer. Bitdefender had less of an impact on my PC than Kaspersky in my tests. Even though both antiviruses are lightweight, I don’t recommend them running at the same time, especially if you don’t have the latest PC build. Furthermore, you won’t have any additional security benefits by doing so.
Indeed, if two antivirus programs operate simultaneously, they might attempt to execute the same tasks on a file, like scanning or quarantining. This can result in errors or clashes. This may cause your computer to crash or freeze.