Another version of "being cruel to be kind". To show somebody some tough love today will save them heartache in the future but may cause a small amount of upset for the reciever immediately after the "Tough Love" has been dispensed. They would suffer more if you let them get on with their life with no interference from third parties.
Leo-"I'm gonna ask that girl out on a date"
Chris-"You'd be wasting your time, you are ugly, overweight and suffer severely from B.O. and thats just your good points, take it from me, she will reject you, maybe not straight away, perhaps she will rinse your bank account first, but you have no future with that girl, I'm sorry mate the writing is on the wall"
Leo-"Harsh words, but priceless advice, I guess thats what they call tough love"
Chris-"It sure is, look it up on the Urban dictionary, on second thoughts, you better not"