Really intending what is said (or planned, etc); in earnest; not jocular or deceiving
Committed.
Without humor or expression of happiness; grave in manner or disposition
Important; weighty; not insignificant
In a serious manner; seriously.
Unfamiliar, not yet part of one's experience.
Outside of one's current relationship; unfamiliar.
Not normal; odd, unusual, surprising, out of the ordinary.
Having the quantum mechanical property of strangeness.
Not belonging to one.
Of an attractor: having a fractal structure.
Sex outside of one's current relationship.