Whoever "Lilith" is, it/he/she/whatever is not recorded in the Bible.
Ejaculating isn't the problem with porn. Demons are not born, they were created perfect angels thousands, maybe millions of years ago, most likely around the time Earth was first created.
The problem with porn is it is sinful to watch others have sex. It's not sinful if you watch porn starring you and your wife, so porn, by definition is not evil, per se.
Then, of course, demons get ahold of you when entering into sin, and try to drag you down ever-darker paths so you can't enjoy good ol' Unlimited Marital Sex like you are supposed to.
It's like trying to get a kid to like natural juice who has been raised on sugar-blast Fruit Flavored Drinks.
Demons are there, ever-ready to aid and assist you in going down the wrong path. Ever wonder why the devil worked so hard to make a wife cost you everything including your life, but porn is free and hookers put out more than an average wife does in a year in five minutes?
Sex is the gateway for conception, which is when eternal beings enter into the Earth to have a body, which gives them authority to operate that mere demons without bodies only dream about. Watch the second Matrix movie to see a parallel for that in the agent who enters one of the Zion residents and uses him for evil.
Second and beginning of third Matrix movies, to be precise.
Anyway, it is far less bad to imagine you banging your dream wife than it is to watch someone else have sex with some underage victim of "Greg Lansky."