FleetingDasein, I'm a Libra with Venus squared Neptune and I very much live this square. I've read that Venus/Neptune aspects are like being attracted to a shadow, or sometimes even having confusion in what gender you're attracted to. When I was younger, I cheated on this guy I was going out with; I cheated on him with a girl. Score 1 for me.
But to answer your question, I don't think this aspect is accompanied by a pathological need for multiple partners; moreso a desire for something that you are unaware of. You could have 5 partners, but none of them will be what you want, and you don't know why. So you'll get a 6th, and that person won't be what you want either. You're just idealistic and trying to find something that isn't there.
With this aspect, the grass is totally always greener on the other side. When I'm not in a relationship, I wish I was. And when I am in a relationship, I wish I wasn't. Venus doesn't like commitment and Neptune loves glamour, thus the infidelity. If I'm in a relationship and something shiny and pretty goes walking by, the grass I'm standing in just got 5 shades duller.
But not only does this aspect imply that you may be decieved, but also that you may be the deciever. Or both. And you may or may not even be aware that you're decieving. I have a book that says of this aspect, "Marital happiness can be endangered by a lack of honesty and directness" and also, "These people are likely to bestow their affections unwisely."
I've also read that this square could indicate someone not being very affectionate, or not being clear with their affections. This is me. I am not affectionate at all and most relationships dissolve because of this. Either way, this aspect to me indicates some sort of honesty or deception problem, on either end. Either you're lying to yourself, or you're lying to someone else, or someone is lying to you. Or maybe you're not clear with your affections, so the other person cheats on you, or vice versa. Maybe you attract non-affectionate people, so you go elsewhere.
Venus is also a planet of feeling secure, and Neptune is a planet of decieving. So I think for Venus/Neptune squares, it's also a problem of trusting someone and feeling secure enough to open up or be honest. Or it't a matter of not feeling secure, so you decieve. It's hard to be faithful if you're not willing to trust the person you're with.
This is gonna sound weird, but this aspect reminds me of dog training. Cause dogs know when their owner doesn't trust them and dogs know when their owner is nervous or thinks that the dog is gonna bite. So if you don't trust the dog, the dog won't trust you. And the way to help that is to gain the dog's trust by trusting the dog. And it's like human relationships because people will reciprocate whatever they feel the other person is projecting. If you're being dishonest with them, they'll do it back.
But also, you could be attracting the wrong people. Venus can not only represent what you are attracted to, but also what you attract. Maybe you attract decietful people, or drug-addicted people (Neptune). Or maybe love is your drug. "Just 1 more, just 1 more. This is the last time. Okay, now this is the last time."
And I'm pretty sure I was cheated on once. But I think I'm more the other side of the Venus/Neptune square. I am attracted to the ideal and what few relationships I've had were problematic. And they end mysteriously. That's another thing with this Venus/Neptune aspect that I think. All the relationships I've had didn't abrubtly and clearly end, they just kind of faded and strangely ended.
But I've actually only cheated once, maybe twice. I can't remember, it was when I was like 16. I'm 25 now and I haven't cheated on someone since I was in highschool. Whoever I didn't have, I wanted. And whoever I had, I didn't want. The same 'ol grass is always greener philosophy. I'm still like that now, but I wouldn't cheat. I'd want someone to be honest with me, so if I was in a relationship and came across something pretty that I wanted, I'd just be considerate enough to break off the relationship and pursue what I wanted.
Venus and Neptune would be great for eachother. Venus is non-commital, and Neptune is an escapist. They both like music and art. They're both peaceful. They're perfect for eachother, but when they form a square, it's confusing. But if they were a couple, they'd argue about decor. Venus would want tasteful and attractive classical art pieces, but Neptune would want lava lamps and psychedelic Grateful Dead posters everywhere.
Neptune wants the best, but Venus doesn't want to commit. Neptune wants to retreat, but Venus wants to be affectionate. Maybe it isn't such a good match after all.
But I think the upside of a Venus/Neptune aspect would be artistic appreciation or talent, or being attracted to artistic people. My brother also has his Venus square Neptune and he is very artistic and creative. And not just with creating, but with appreciating. He deeply loves art and appreciates other people's artistic talents. My brother is also attracted to and attracts the artsy girls. Also, my brother and myself are obsessed with music. Venus and Neptune are both musical and artistic planets, so although they form a square and create some challenges with eachother in relationships, the one thing they can agree on is music.
Also, another upside with this square could be being idealistic about love and relationships. It may be more of a curse than a blessing, but I totally think that I'll find my someone out there somewhere....maybe? Probably not. The only way I'd ever feel secure and confident enough with a relationship is if I met every single person on the planet Earth. Cause I honestly find it difficult to settle down when I know that there are people out there in other states and countries that I have never met.
Although it may be an exhausting aspect to have, it's still good because Neptune won't let you give up on the quest for the ideal. Since when is wanting the best a bad thing? I'd rather have nothing than something I don't want. What am I gonna do, settle for something I don't want and be unhappy? I wouldn't want someone to settle for me if they wanted someone different. And relationships are difficult no matter where your Venus or Neptune is, but this aspect sure doesn't help.
I'm sorry, I sure did write a lot. I have Neptune in my 3rd house and I have difficulty controlling my brain. Maybe Neptune heard I was talking about him and decided to contribute to my obscure rambling about a Venus/Neptune square.