I've been lying to my significant other about my age from the moment we met.
Why would you do that?
Because I don't want them to know my real age.
Lying about your age is not okay to do. Doing so will cause a person to believe that they may have more in common with you than they do.
I don't think it's that big of a deal.
You lying about being younger may not seem bad to you, but any lie in a relationship can ruin it. You need to be very careful that you don't hurt your loved one and have him no longer be able to trust you.