virtually dry humping
When you and a buddy "poke" each other back and forth long enough on Facebook, you get hot for each other.
Jack: pokes Jill
Jill: pokes back
Jack: pokes back
Jill: pokes back
...
Jack is virtually dry humping Jill.
Jill: pokes back
Jack: pokes back
Jill: pokes back
...
Jack is virtually dry humping Jill.