Another thing to keep in mind is that the anus absorbs water quickly and can dry out easily when you're using a water-based lube, according to sex therapist Kyla Black . Therefore, silicone-based lubes are usually the safest bet. That said, if you're having anal sex with a silicone toy (like a strap-on or a dildo), or engaging in anal play with a silicone butt plug or beads , go with a water-based lube and just make sure to use a lot. (TL;DR, Silicone breaks down silicone, and you don't want your toys breaking down inside your butt.)