What is the right definition of perverted?

Perverted to most people means being confronted, or forced into dealing with, sexual behavior they don't personally like. No one likes receiving messages they have stated they don't want. It's not so much the specific sexual content but the fact that it's being displayed before someone who hasn't requested it, or who is clearly put off by it. Flashers in a park don't expose themselves to little old ladies, or small children, because they think those people will like it, but because theydon't.

per·vert·ed
pərˈvərdəd/Submit
adjective
(of a person or their actions) characterized by sexually abnormal and unacceptable practices or tendencies.
"he whispered perverted obscenities"
synonyms:unnatural, deviant, warped, corrupt, twisted, abnormal, unhealthy, depraved, perverse, aberrant, immoral, debauched, debased, degenerate, evil, wicked, vile, amoral, wrong, bad; More
(of a thing) having been corrupted or distorted from its original course, meaning, or state.
"this sudden surge of perverted patriotism"

Staring? Online you might mean stalking. In real life, people stare at those who are different or unique. Not a bad thing, really, to be an individual. Bold means different things to different people. I guess it depends upon the individual. I would say perverted is continuing behaviour that is offensive to me when asked to stop. And it also involves sending cock shots or saying suggestive things when one is a stranger to me. I flirt with my friends here. My line is pretty clear. And I will clearly state when it is crossed or one is in the danger zone. Great question.

I think of it as involving a persistent obsession with some aspect of sexual activity. So someone who likes women’s feet or watersports, say, isnt necessarily a pervert just because they have a somewhat unusual sexual interest. But if they incessantly impose their interests on others, to the exclusion of other subjects or a partner’s other interests, then I guess that feels perverted to me.

The consent of the person to whom it’s directed. Unwelcome, insistent sexual attention can be considered perverted and even predatory if the object has already made her (or his) objections known.

There is no line. Nor should there be. It's all relative.

someone who ends up fucking your gf while you're sleeping in the next room 😅