As Caldrail suggests though, In "Life of Augustus" Suetonius is quite clear with the description.
Ah - now here we have it! He had the triumphs 'voted' to them. That does not mean they celebrated them. Hadn't Agrippa set the precedent that it was customary to refuse? Cf. Graves' translation: 'Augustus showed equal generosity in recognising military talent, by letting full triumphs be voted to more than thirty of his generals, and triumphal regalia to an even larger number.' It is an interesting point that Caldrail raises, however, for modern historians seem to be unanimous in stating that no Triumphs were celebrated during his reign apart from those by members of his family. Have the moderns misinterpreted Suetonius? Did the generals celebrate Triumphs after all?
This has got me wondering now.... Well spotted, Caldrail!
ETA: Our own UNRV article HERE seems to take this idea for granted too. Have we all been labouring under a misapprehension? Now I want to find out exactly where in our primary sources it says that he would not allow triumphs to be celebrated by non-related men. This is turning out to be quite a fascination for me.