The other thing I wanted to mention but put it off because I wasn't sure how it may be received is that men (and women) like this can tend eventually toward violence because they don't know how to handle their feelings if their questions aren't answered in a way that satiates their needs.

It really can start out curious, leads to need then escalates to confusion and anger. This personality is relying on you to fulfill their every need, literally and if you do not fall into that pattern willingly there can be a tendency to try to force you into it.

The one thing that really rang true was Byz's comment about taking your fiance off the pedestal and see him for who and what he really is before you marry him. His problem isn't innocent and it can be much more than simply irritating. If he does not gain his security it will escalate and that causes me concern for you.