Is this person hideing something?

If someone claims to love you, plans on marrying you in 2 months, pay"s the rent is a good provider, father, is romantic, suprises you with gifts on your birthday, surprise dinners and is very affectionate and attentive. However this person has their cell phone on lock around you, and gets angry when asked to allow me to see and listen to his messages. This person explained he would do whatever it takes to keep me and make me his wife. Ladies and Guys he has something to hide? If there is nothing there he should prove it. When you consider marrying someone no part of your life should be closed to your spouse. Just causes problems later. What do you all think. THANKS FOR YOUR RESPONSES