who is making the post. Is it you or is it your wife?
If you are that worried your spouse is going to cheat on you just have their login in a different browser and go check in from time to time.
It's just so weird. Has anyone seen people that aren't LDS do this because I haven't. Lots of people put a picture of them and their spouse as the profile pic, but the joint account is just being the weirdest weirdo's in all of weirdville.