Do you think it's ok to check your husband's phone? Why or why not?

I would not suggest anyone doing that, even when it's the other way around. If you are compelled to check your partner's phone, that's a clear sign that you do not trust him enough or that you're feeling insecure about something. Just because your married doesn't mean there are no longer boundaries between the two of you. Husbands and wives still want their privacy.