If these angels were merely manipulating matter (vs. somehow taking on real material bodies), the notion of "lust" wouldn't even factor in, as lust requires the interaction between the matter and the spirit, where the material could cause a reaction in the immaterial (generally the lower, sensible nature) ... unless somehow theirs was a purely intellectual "lust" of some kind, vs. the normal human lust caused by concupiscence in the lower nature.
Scripture doesn't actually say anything about "lust" though, just that these women were fair and that they took them as wives.
The sons of God seeing the daughters of men, that they were fair, took to themselves wives of all which they chose ... Now giants were upon the earth in those days. For after the sons of God went in to the daughters of men, and they brought forth children, these are the mighty men of old, men of renown. [Genesis 6:2,4]
And given Pope St. Clement's exegesis, he supposes that they took human natures upon themselves, which, if I'm reading correctly here was derived from covetousness, which can be purely intellectual, with lust being a form of covetousness.
having assumed these forms, they convicted as covetous those who stole them, and changed themselves into the nature of men, in order that, living holily, and showing the possibility of so living, they might subject the ungrateful to punishment, yet having become in all respects men, they also partook of human lust, and being brought under its subjection they fell into cohabitation with women;
So it, at least based upon Pope St. Clement, doesn't really support that these sons of God were themselves of a hybrid angelic-corporeal nature. But theur fall came once they subjected themselves to a corporeal form, not unlike what the angels in Scripture have done, that they gave into the passions associated with that form.