Lovers often speak their love for each other to one another....
it as a “given” and operate in it when together.
absorbed in each other...
Friends stand side-by-side, absorbed in some common interest, goal or philosophy.
Eros love is (healthily) between two, and only two.
Friendship can increase in its enjoyment by the addition of two,
three or more so long as the interest, goal or philosophy is somewhat the same as a common bond.
Friends pull from the herd in becoming friends buy would appreciate a 3rd, 4th or 5th party on the same terms.