On StudySpanish.com, it says that when using D.O and I.O pronouns together, you should change the "le lo" to "se lo" to avoid the tongue-twister effect. Here is an example of what I mean:
Nunca se los compro, instead of Nunca le los compro (I never buy them for her)
But what about in this example that they have on their website?
No se lo tengo.
I don't have it for you.
Why wouldn't it simply be
No te lo tengo because there is not a tongue-twister effect, right?
Muchas gracias!