I've had quite a big mix of results with telling women that I'm into women getting mounted by dogs or horses. I did admit to one that I had experience receiving the penetration.
-By my second girlfriend, about 3 years after losing my virginity I knew about male dogs mounting humans and had experience. My big boxer used to wait outside my bedroom while I had sex with my 2nd girlfriend. I was so tempted to suggest he stay in the room. This girlfriend was interested in fisting, after first telling me to see how many fingers I could fit into her during foreplay one day. I told her that I'd read the book, A Hand in The Bush, The Fine Art of Vaginal Fisting. A couple of days later, we tried it. Success! Her standing up leaning back against the bathroom counter, and me on my knees. She enjoyed a rather big shampoo bottle too. I think she might have tried getting mounted, maybe. I was afraid to ask.
- 3rd and 4th sex partners were flings that I was not attracted to all that much. They both were willing to try getting mounted. Again, fisting was something I talked about first. One of those women even hoped for a threesome with her sister and sis's hubby. She was an army chick, and not afraid of much!
- My 5th woman to have sex with ended up being a year and a half long relationship. She was adventurous enough. I told her about swinging first, or her fucking someone on the side alone. She didn't condemn me, but would say, "why". After a few months I told her about sex with dogs. She had a lab x rottie pup. He was too young, but growing fast. I think that if I had stayed with her, there's a 50/50 chance she would have let him lick her. She was living in the far college town that I wouldn't stay in though. We went our separate ways.
I started talking to my first love again 6 years after our breakup. We were about 23. She was a new mother. Our conversations went very far on the phone. She asked me a lot of sexual stuff. I was the religious one back when we dated, and broke up over sex before marriage. We were like bunnies. She loved to feel stretched. I had nearly fisted her back then not knowing it was a sex act, and just both of us were curious as to what would fit (barely pre internet). So, after telling her that I now knew fisting was a sex act and had experience, I admitted to zoo sex fantasies and an interest in watching. She told me that her and a friend had read stories, but that she wouldn't do it. After that night, she never spoke to me again. :-(
- Fast forward to age 29 (a few years of vanilla swinging happened in my mid 20's). I start dating a woman that is polyamorous and into BDSM. I also discover Bad Dragon toys this year on Beastforum. I didn't tell her about my experience in zoo stuff till after almost a year of dating. I had answered a BDSM kink sheet early on, and didn't admit it on there with the beastiality question. She got angry at me for not telling on the BDSM list. She has a Ph.D in psychology, so that factored in, I think.
I ended up buying a horse cock dildo from Bad dragon 3 years into the relationship hoping that she would try it, then maybe get curious about horse cock in real life. This seemed more likely to me since she was already a horse woman that rode horses all of her life, on and off when possible. Well, she wasn't interested in the horse cock dildos, but did enjoy me using big human cock dongs on her. Then, a couple of years later she was interested in trying the non-realistic artsy dildos from Bad Dragon that were more humaniod.
Well, she ended up getting into a same sex relationship and that really got most of her attention. She was big time into fisting the other person's pussy, and that person would rail her with a big high quality silicone cock. It was amazing to see!
She admitted to want to move to another state with this person, so we broke up, but she tried to revive things with me first by offering for me to use the horse cock dildos on her. I said that it felt like she was doing it just for me (silly me), and didn't do it. She may have started to have some slight interest in zoo sex. She had known me 6 years by then and trusted me. She had also really enjoyed cleaning may gelding's cock (castrated male horse). She would pull the smegma off and soap it. She seemed to like it more than a regular horse chore. I just kept quiet, not wanting to be pushy. He'd actually drop his cock fast for her to clean it. We joked about it a little, but i was probably being too timid, and should have construed it with zoo fantasies a little bit.
After we broke up, one of her other guys that she left too, said that she didn't oblige me more in my zoo fantasies "because she has a Ph.D. and is afraid to take the slightest risk that could cause her to loose her license". She did ask me once to show her zoo porn on my laptop. I'm not sure if I showed her pics or vids. I think pics were as much as she'd look at. I often wondered if her other boyfriend meant that she'd have looked at more zoo porn with me, or actually played with a stud horse (even just stroking him) if she didn't have a professional license to risk.
- I dated 1 woman for six months while dating this poly woman. She was kinda curious, but reserved. She said that she "might would be willing to get mounted". She preferred and open relationship. She didn't seem to want to use condoms, but did because it was my polyamory rule with the other people in my circle. She had experience both fisting and being fisted by women. She was bi. I think she really would have bent over for a dog if the dog bonded with her. She'd have probably been more zoo and not just into it as a wild kink.
- Another woman I talked to for a month while in the poly group, she watched a zoo video with me. She admitted to letting her female dog lick her pussy juice from her fingers, but claimed to not go further. She said that she might would let a dog mount her one day. I couldn't read how serious she was. She was actually a successful fiction writer, a published author.
- Two women that live 300 miles away and have been friends with benefits with me over several years, and years between us fucking, on some days said they'd get mounted, then on other days said "no, probably not". One of them said that she do it if she were blind folded, had a drink, and she were tied up for it. She said the same about fucking one of my friends that way, and it was a serious fantasy for her to feel a friend fuck her while restrained. So, I think that she really would have been willing to get mounted within the context of a BDSM scene, but she would probably not "let herself become zoo". She sees herself as being quite traditional, but wants rough sex at night, BDSM stuff.
- I had 4 hookups in the years since then. I didn't tell them anything about zoo fantasies, but one dog girl tempted me. I held back though, and glad that I did looking back. It was a work romance, and it did not end well. I left that company.
- My current casual girlfriend: I told her in the first month. She is fine with me being into that. She expressed mild curiousity early on, but it didn't seem strong enough to me. So, I haven't talked to her about it. She has not brought it up again either.
** To this day I'm not sure that I'll get to be in a relationship with a woman that actually gets mounted.
** My advice: talk about other kinky or adventurous stuff first, and probably days apart. The incest fantasy stuff is practical, especially if you life is such that no family is near you or possible for that. She'll see it more as pure fantasy. If you have sexy family members near you, be more careful with that one!
Big dildos- Well, not all zoo women are size queens, but there is enough of an overlap that playing with big toys, and random odd insertions, can possibly lead to a conversation about dog cock.
Threesomes or nonmonogamy- If you or her like threesomes, or her being able to have sex with someone else on her own, that may be a route. Be careful though, they may be against zoophilia, but a willingness to go against the grain and be non-monogamous is a hint of "openness to experience", and also the willingness to do what some people say is wrong. If she is down with cuckolding fantasies, bigger dicks than yours, and creampies, that's all stuff that you can tie into a conversation about why try beastiality.
Random stories- tell of someone mythical story, erotic fiction, intersting history, or other thing about zoophilia that could just be considered interesting or novel, even aside from any kinkiness. I think this is safer than porn, but you be the judge.
zoophilic love tendencies- is she the type to see it more from a love perspective? A deep way to bond? "Why should there be rules against that if the male dog wants it"? So, if she seems to possibly be more of a zoo than looking at it from a kinkiness approach, give that route some consideration.
There's no one best way to bring up the subject to everyone. Very slowly consider the most closely related thing that you can already talk about.