I've had several threesomes. Given your situation, this is my recommendation but I have no idea if it would translate into Thailand.
What I did is I had a main girl, I told her look I can't be with just one girl. This led to the agreement that I could only fuck other girls with her there (aka threesomes) and otherwise we are exclusive. Of course I wasn't exclusive but this gave her the piece of mind to do it with me. The hardest part was finding a unicorn as they call it (because it is so rare to exist a single girl wanting to be in part of a girl/guy threesome). Seems you have found your unicorn, kudos to that.
We'd always meet at a bar very close by to my apartment or hotel. We'd have drinks and I'd let the girls chat because they are girls and they like talking to each other. You have to remember the curious girl is there to see what it's like to be with a girl. Not you. She can have dick any day of the week. So you are the accessory and your fb is the main component. Act that way. Let them talk and just once in a while jump in. Go to the bathroom so they can talk privately. After about 30 min to an hour, have your girl go to the bathroom so you can get some alone time with the unicorn. Just be nice and friendly and run game as usual. When your main girl comes back, suggest you go back to your place and have a glass of wine or whatever.
Once at your place, I've found it best to have your girl initiate things, which is just a makeout. Let it escalate from there and then jump in after about 5 minutes.
I may have left out some things so let me know if you have any questions, I can expand. Of course who knows if it this will work for you, and I'm not running through threesomes on a weekly basis, but I have had this situation before with a fb and bringing in the unicorn.
What I did is I had a main girl, I told her look I can't be with just one girl. This led to the agreement that I could only fuck other girls with her there (aka threesomes) and otherwise we are exclusive. Of course I wasn't exclusive but this gave her the piece of mind to do it with me. The hardest part was finding a unicorn as they call it (because it is so rare to exist a single girl wanting to be in part of a girl/guy threesome). Seems you have found your unicorn, kudos to that.
We'd always meet at a bar very close by to my apartment or hotel. We'd have drinks and I'd let the girls chat because they are girls and they like talking to each other. You have to remember the curious girl is there to see what it's like to be with a girl. Not you. She can have dick any day of the week. So you are the accessory and your fb is the main component. Act that way. Let them talk and just once in a while jump in. Go to the bathroom so they can talk privately. After about 30 min to an hour, have your girl go to the bathroom so you can get some alone time with the unicorn. Just be nice and friendly and run game as usual. When your main girl comes back, suggest you go back to your place and have a glass of wine or whatever.
Once at your place, I've found it best to have your girl initiate things, which is just a makeout. Let it escalate from there and then jump in after about 5 minutes.
I may have left out some things so let me know if you have any questions, I can expand. Of course who knows if it this will work for you, and I'm not running through threesomes on a weekly basis, but I have had this situation before with a fb and bringing in the unicorn.