Anyone ever been successful getting their gf into a proper threesome?

A dick that is not yours will fuck her. You will be a cuck.

No he won't. He will be a stag. A cuck is actually different. In both cases there are other mens dicks involved, but the important difference is who will be the dominant person in the relationship afterwards. If the man stays dominant, he's not a cuck.

My gf's bff would always get drunk with us. I had suggested it to my gf, but not as a 3some but under the premise that I'd just want to see them playing with each other's titties, because everybody loves titties. That I'd not fuck her etc.

She agreed kind of. That Friday her bff came over (she was small spinner 90lbs flat tits banging body and way hotter than my gf) They filled up a bubble bath and got in together. Hot watching them take each other's underwear off. They washed each other all over til the water got cold. Then we moved to bed, made a sandwich of my gf. I spent most of my time fucking gf and fingering spinner bff who was shopping wet. She ended up going down on my gf and I had my chance, I slid into her and came in about 30 seconds, plastered her insides. She knew I came in her too but never said anything to my gf who I don't even think realized I had been inside her bff. The bff texted me later and I had to go buy her a planB.

hmm... didn't think about it that way. i was thinking of it more like drugs. i done a few, but when i was finished with them, i was done with them. that wasn't the right perspective though because now that i think about it, the more I've tried to address it, the more it needs to be addresses. she's gone from wanting to do an erotic photoshoot with a black co worker of hers to making us watch dark x scenes at dinner every night, now she asked me to set this up and i thought if she gets it out of her system, she'll get over it, but it might just make things worse.

this. just because another guy penetrates your gf doesn't mean she stop being your girlfriend. i hate how Yas Forums always gets this so wrong.

If it's a random chick neither of you know it's a 3some, but if it's your gf you become a cuck.

a dominate cuck is god like masculininty. you control your gf's orgasm in every way, no matter who she fucks.

I'm in a similar situation, user.
GFS bff has been over every Wednesday and then either stays 2 nights on the weekend. She just got back from overseas and is broke, way hotter than my gf.
I've been giving her weed, buying her coffees and cooking them meals, getting them drunk. My gf let's me fuck her once a month if I'm lucky (she's rich and gross)
BFF is 8/10 and very my type.
She asked to borrow one of our cars so she doesnt have to borrow her mums..what should I ask for in return? How do I stop my gf cockblocking me?

Yeah but it kind of ended our relationship not straight after but soon after, but real no regrets though.

You should just get her to watch y'all fuck one time. Then spring it, call her over.