textual relationship
1. Typically a friendship or bond that is limited to the glass screen, or smart phone.

2. A friendship that occurs via text which is usually that status of "close friends", but is basically nonexistent in "real life".

These friendships usually occur under the nose of other friends. More often than not, these "close" friendships occur between two people you never thought would talk to each other.
Jen the scene kid and Scott the Jock were a part of a 6 person group of friends. Their one-on-one chemistry in the friendship was nonexistent until Scott picked up "them digits". Several months later the other 4 friends were utterly shocked when Jen and Scott started dating since they never talked to each other in person. They concluded that they must have been having a secret textual relationship.