Why stop there. Just keep on using all the usual names, but make them all unisex.

For example, if Tony is texting to Anna, He will have no idea if Anna is a he or she until they meet face to face. Also, Anna might be expecting to meet a woman, but will be surprised to find that Tony is actually a guy. Then, Anna tells Tony, that they should really talk to Karen for some weight lifting tips because he’s been lifting for years.

Sounds confusing, but you’ll actually know who is married and who is still single. Pretty handy, eh?