A way of describing an ambiguous relationship between a man (or woman) and another woman. The individuals have
sex, and have a close personal relationship, but the woman in question is not defined by her
lover as a
girlfriend, so she can only be referred to as a 'girl thing'.
person 1: what's up with chris and laura, they live and sleep together, are they going out?
person
2: no, she's just his girl thing.
Are they
friends with benefits? Are they in an open relationship? We
don't know, so we'll call her a girl thing.