Feelings aren't instinct. (Feeling disgusted or sexually aroused or aggressive isn't an instinct.)
Instincts, by definition, are complex behavior. (Think birds building nests; nobody teaches them to do that, they are born with that knowledge.)
Sexual arousal is neither complex nor behavior. It is a simple hormonal state.
You're using a colloqual meaning of "instinctive" that is unscientific and wrong.
But that's far from being the only source that defines 'instinct' in a way that doesn't align with what you're proposing.
Humans do have instincts.
[1] https://www.britannica.com/topic/instinct/Instinct-as-behavi...
Including the possibility that Gandalf and Harry Potter fly in on a Raelian flying saucer and solve climate change for us.
In reality, however, no instinctual behavior has yet been found in humans.
Humans invented the concept of exoskeletons, too; inventing a concept does not imply having the concrete feature referred to by the concept.
Yes, humans have instincts, but inventing the concept of “instinct” is unrelated to that.
Humans don't have instincts. That's what separates us from the other, lower animals.
P.S. Urges, drives and desires aren't instincts.
P.P.S. Technically not true, the human being has a couple instincts related to breastfeeding, but they are supposed to disappear after a couple months in a healthy human baby.