So, what do you call the male person in a serious, committed, lifetime male/female relationship, if they're not married?
There is currently (I feel) no appropriate word in our language:

• I don't like significant other;
• the word boyfriend doesn't seem to be a good description for someone of mature age;
• the word manfriend (egads) clearly doesn't work;
• companion doesn't give the right emphasis to the seriousness of the relationship;
• life partner is a bit stilted.

I propose  husbandnot  ( HUS-ba-naut, it rhymes with astronaut );
he's like a husband, but there is no legal recognition of this fact.

Other suggested spellings: husbanot, husbannot, husbanaut.
Send me an email (using the comment form on my homepage) if you have strong feelings one way or the other.