It's a cute nickname for your boyfriend. Instead of just calling him "Hubby" or "Hubs."

well this is the nickname my dad called me when i was younger constantly blowing bubbles apparently
19 years now i've been bubba :D

well thats not only for guys cuss
my bff her girlfriend calls me that
wierd i knoe but i dont knoe byebyebyebye

also means...

GRANDMA, in some language i fail to rmbr ! L0L. cos i called my boyfriend this name & this person told me it`s grandma in their language.