paramour
partner, girl/boy freind, or if married, wife/husband.
A person who is engaged to be married is a fiancé if male or a fiancée (note the additional e) if female. Both words are pronounced identically.
Such a person would be an accomplice or a partner in crime.
A person that is about to get married is called a bride (female) and a bridegroom(male)
The Bridegroom.
A hacker is a computerphile who uses his expertise for illicit access.
Illicit Trade
a female who isn't married is Mademoiselle
If they call out another person's name that you aren't, also if the person is acting weirder then usual.
A person who is not married to a woman but has sexual relations with her is called her lover.
Grammar has nothing to do with it. You should know a 'partner' well enough to know what he, she, or ze wishes to be called. If you don't know your partner's prefrence, then you should re-evaluate your relationship with that person (you're not as close as you thought).
Sadly you can't call your partner on Tenchu Z itwould be good if you could but no.