[Dr. Sivana]

When there has been sexual intimacy involved with either female. Duh.

The sexual intimacy without a marriage or at least an engagement isn't much of a promise at all. No shortage of one night stands with no commitment whatsoever on either side.

[Albion Wilde]

There is a distinction to be made between one-night stands and “boyfriend”, which your post 5 was questioning. We don’t know whether her status was agreed-upon or wished for, but my answer to your question was about persons who are okay with being known by their female counterpart as “boyfriend.” A “boyfriend” does not have one-night stands, either with his “girlfriend”, with whom he has an ongoing relationship, or with other women while he has a “girlfriend,” unless he has a death wish.