Want to try mfm Threesome girlfriend

We've been together for 3 years. Im 22 and she's 21
Im her fist and she's my first.
We both love sex and marathons are our favorite i go to to the point where i ejaculate dust in the 6-8th round.
We are so open to new experiences, we have tried so many things: Anal Role-play, Outdoor Sex, Golden Showers etc. She's like a "sex genie" where every wish or desire i have i just ask her and she loves granting my requests, no questions asked.
She says she knows she's in good hands and that I know how to pleasure her so she would never doubt me and my requests when it comes to sex.
The past few months I started having a thing for mfm threesomes and when i imagined my gf getting pleasure and pleasuring 2 c*cks made me horny af. Not sure how it started, i think it's because we love recording ourselves having sex and and when I watch the videos days after im astounded, she's so hot and so damn good at sex I can't even explain it.
I don't watch porn anymore just beacause, in my eyes, she's way better than any pornstar I've ever seen.
Maybe it's the idea that she's so great i feel the urge to (brag) tell other men: look what a sexy woman I have.
A week ago i told her I'd love to bring a toy and play. And like always she said yes.
So i bought the most realistic dildo i could find, The biggest size available was exactly the same size as me (7inch)
I made 30 min video of her getting f"cked by me and the dildo.
What i loved about it and made me hormy as hell is that she didn't gave more attention to my c*ock than the dildo, She handled that piece of rubber like it was a real c*ock that wanted the same pleasure as me.
It was 50-50 me and the dildo and damn she knew how to pleasure 2 c*ocks.
She sucked and fucked the dildo like a champ.
When i was doing her from behind she was sucking that dildo like she would mine, and even better.
She kept saying how much she wants 2 c*cks, one in her mouth and one in her p*ssy, she loved every second of it.
Days later when she watched the video too she loved it and wanted to do it again.
I did not ask her specifically about her thoughts on a mfm, I had asked her once before jokingly and she said there's no way she would do that.
I asked her:
-While we were doing that did imagine anyone (a man) beeing the dildo. Did you imagine suck*ng someone we know or was it an imaginary man?
- I did not imagine any man at all not even imaginary.
I was just enjoying the feeling of beeing filled.
Can that be true? Because if she's hiding the truth from me then it's a big deal. We've been open with each other always and i want her to be honest with the thought of a threesome too.
Should i mention the threesome to her?
Is it gonna ruin our relationship?
Is it gonna be worth it?
Is it just a temporary fetish (just like the golden shower I once had) that i will regret later if I do it?
Mayne she's just granting my wishes like she always does?
I don't want her to have sexual fantasies that she can't talk openly with me.

 

You're both very young and have time to explore fantasies. I'd think after 3 years you would know her fantasies, and her yours.
As far as sharing her, that's a big step. What tripped this fantasy for me was read a Penthouse Letters 'Wife Sharing Edition'. I read it cover to cover many times, and highlighted the stories I found hottest. I had to leave town for a couple of days and I left the mag on my wife's (ex now) nightstand. When I returned home I found her on the bed reading it. Lots of questions but she seemed intregued. She had earmarked a couple stories she found interesting. While my favs were MFM stories, her's gravitated towards being a Hotwife, dating outside of the marriage. Well that night I broke the ice. While having sex missionary she had already had one orgasm, and as she was getting worked up for #2 I whispered in her ear "Your husband is really getting off watching me fuck his wife". She came hard almost immediately and so did I. She asked me afterwards if that was something I really wanted to do (we had been married a couple years by now) and I said yes, but it was up to her. Well shortly thereafter one of the trainers at her gym asked her out, even though he knew she was married. She came home and told me, and asked what she should do? I again said it was up to her. Well after a couple dates she always came home hot and bothered. They hadn't had sex yet, just a lot of kissing and roaming hands. They say the third time's a charm and she ended up at his place having sex........twice. When she got home and told me this I threw her on the bed and fucked her harder than I had in a long time. When she started giving me details I lost all control and gave my wife her third load of the night. That started almost weekly hookups for 6 months. And if anything OUR sex life ramped up. Never did have a MFM with him, nor did I get to watch. She was a Hotwife, him her Bull, and me her Stag.
With my current wife (living together before we were engaged) it started similarly. Reading stories, role playing using her lifelike dildo, started watching MFM porn. She did ask if I wanted MFM as a way to get a FMF, and although I wouldn't have turned it dow, I said no. That seemed to put her mind at ease. As with my ex, she got off when I said that your BF is really getting off watching me fuck you. Same results......a massive orgasm. The night that really shifted the balance she and I were in a 69, her on top. While she sucked me I was licking her clit and working her dildo in her pussy. I said I'd bet a real cock would feel better back here. She raised her mouth off of me, looked back at me and said "Then find me one!" We looked for months.....didn't want CL crazies. Then like a gift from heaven, one of my best buds from college let us know he would be in town visiting his family for the holidays. He had met my fiancé a couple of times, and she thought he was very attractive and I could tell he felt the same about her. We took him to dinner and shared a bottle of wine (my suggestion.....don't drink too much. Just enough to ease the nerves but not enough to damper the senses). We went back to our house and although it started slowly, things heated up and soon we are all naked on the living room couch and then the floor for round one. Amazing sex, especially for her. Many orgasms from 4 hands 2 mouths and 2 cocks. Once we cooled down from round one we moved to our king bed and started round two. The hottest parts were watching her orgasm with him, watching them kiss, and him cuming in her. As soon as he left we had passionate reclaimation sex. Awesome. She fell asleep with four loads of cum in her. In the morning she apologized for letting herself go and acting slutty. I told her I loved it and her even more. She smiled and ask if we could do it again before he left town. Two nights later we had him again, with the same marvelous results. 3 mo later we were married, and a month or two after the ceremony he was back in town, fucking my new wife! Erotic watching her guide his cock into her with her left hand, and seeing that wedding ring. We did have several more MFM with him during the coming year until one day my wife said she couldn't do it anymore! WTF! WHY? Said it was something a proper wife and mother shouldn't be doing. My friend and I were so disappointed. So that was the end of that!
Sorry this is so long. I tend to get long winded reliving my sexual pasts. Good luck with your gf.

 

You could drop a hint. Might not want to come right out and ask. I had several before my girlfriend had her first. But take your time, don't rush into anything.

 

She definitely wants it. Just keep talking about two cocks and warming her up to it

 

I let a friend go to my house and hide in the closet while I drove my girlfriend home. Then he watched me strip and screw her in every way possible. she parented to pass out and he watched the whole thing in a lighted bedroom. She new he was there but he didn't know that. we were at it for about an hour.