Can this be shared?

Since you're fluid-bound to your wife, I *suppose* you could share it. However, it's not 100% silicone and will hold bacteria. It's not sterilizable. So you definitely don't want to use it in both the rectum and the vagina. Perhaps you should try the Nexus G-rider which could be used for both vaginal and anal play, not to mention is 100% sterilizable.

Or, you could try this by Pipedream. It's very similar to what you are suggesting above, but is 100% silicone and can be sprayed down with a 10% bleach solution that would make it safe for anal and/or vaginal play (though likely to be too slender/short for vaginal).