The tangent of a relationship

The trigonometric tangent is defined as:I hereby define the tangent of a relationship as the time spent together vertical divided by the time spent together horizontal.

Table I. Tangents of common relationship types.
Theta_____Relationship
90 deg.___Friend, coworker, etc.
45 deg.___Friend with benefits
30 deg.___Spouse, significant other
0 deg.____Booty call you can't stand
Amusing etymology:
1590s, "meeting at a point without intersecting," from L. tangentem (nom. tangens), prp. of tangere "to touch," from PIE base *tag- "to touch, to handle" (cf. L. tactus "touch," Gk. tetagon "having seized," O.E. þaccian "stroke, strike gently"). First used by Dan. mathematician Thomas Fincke in "Geomietria Rotundi" (1583).