Why do Mormons/LDS refer to God as "Heavenly Father" rather than "Our Heavenly Father"? I have noticed a very subtle distinction in the way Protestants and LDS refer to God.  When  Protestants pray to God, he may address Him as "Heavenly Father", but when they speak about God, they seem to refer to Him as "Our Heavenly Father".

However, the LDS people that I have known and met seem to refer to God as "Heavenly Father" (without the Our) in both situations--as a direct address and as an indirect address.

I really don't know if there is any reason for this.  Perhaps it is just cultural to each group, but I thought I would ask anyway as it does make me curious.
It's not significant. It could have to do with anything from how they're raised, to how they prefer to speak, to language and dialect, to setting, or to anything else. Mormons will say both "Our Heavenly Father" and "Heavenly Father" interchangeably.