Many people over the age of, say, 30, feel weird about using the word "boyfriend" or "girlfriend", because they feel that it implies a young person.
Are you kidding? My sarcasm detector is failing here.
Failing that "Other Half" or "Baby Mums".
I know many people, and none of them refer to their
significant other as a 'partner.' For example, I know
one guy that is 50, who refers to his same-aged
significant other as his 'girlfriend,' and it doesn't
seem to bother him that 'girl' is in the name instead
of 'woman.'