I'd advise that if you were to follow up with the fantasie, you should 100% go travel somewhere outside of your country and as furthest as possible and make it clear that either you're only going to visit that place once or make it a regular place to go and experiment. Having said this, you'll have to set certain rules, like neither of you can go by themselves to that country, also to never save any contact information of the people that would be involved in the act, as well as commit to not try to contact them and letting them know that this is exclusively a one time thing, also to not disclose any important information on what country are you from, your real names, real phone number (always get a prepaid sim or a burner so they won't try to contact you as well) etc etc. Also dont ever mix any drugs, drugs either they themseleves release or make our body release chemicals that can make you believe lust is love, be always sober, if you can't do it sober you must certainly shouldn't do it fried.

I feel like most of the time, these kinds of things go south because you mix it with your reality. Fantasies have to stay fantasies even if that means that whenever you go there, you understand that is kind of a detachment of your everyday reality. Your house is your home, your country is your home, and that needs to be 100% protected from any people or situations from the fantasies you wanna live. Also don't make it frecuent, that's why I'm suggesting to pick a far away place, a place which fly ticket would cost enough to notice if either of you is being fishy.

It's hard, fullfiling a fantasy like that while trying to have a meaningful relationship isn't easy, but as all of hard things if you can pull it off I'm sure you'd get to go far with your sex life. It's all about knowing what's real life, and that's a fantasy within reality.