In relationships, this Neptune reaches for a depth that puts a lot of people off. A surface romance bores them quickly; they're after someone they can sit in silence with about the things that matter, someone unafraid of heavy subjects, someone who has been through their own shadow and come out the other side. In my experience, people with this placement often fall for a partner with a complicated history and read that complexity as a sign of authenticity — as proof that the connection is real.
This is where the dangerous swap lives. Depth is easy to confuse with destructiveness, a mystical bond with dependence, karma with a habit of putting up with things. I watch it again and again: a Neptune in Scorpio stays for years in a relationship where the partner drinks, strays or is simply not reachable, and describes it in the language of "we have a complicated bond", "we're karmically tied". From the outside the imbalance is obvious; from the inside it feels like a mystery you can't walk out of without betraying yourself.
The physical side tends to be intense and, often, to arrive early. The question is rarely whether something is allowed; it's how far down it goes. The body becomes an instrument for knowing another person — no less important than conversation or the daily business of a shared life.
The healthier version of this Venus-touched-by-Neptune looks roughly like this: a relationship in which both people hold up a mirror to each other's darkest corners without fleeing and without dragging one another to the bottom. That asks for a certain psychological literacy — talking about boundaries, and being able to say, at the right moment, "I can't carry this between the two of us any more, we need outside help." Without that culture, the placement does tend to produce a run of heavy romances, each one feeling fated at the time. None of this is fixed in stone; it's a pattern worth watching in yourself, not a script you're bound to follow.