All relationships are mediated by forces.
The four fundamental forces of the Universe are:
Gravity
The weak force
The electromagnetic force
The strong [nuclear] force
Each of these has a counterpart in human life:
Stupidity (causes everything to clump)*
Ethnicity
Sex
Love
For clarification, “relationships” here only applies to the last two. I hope this resolves your problem.
*Like gravity, stupidity affects everything.
