Things you wish you knew or thing you could’ve done to mentally prepare.

So me (30m straight)and my gf (29-bi) had a wild night this past weekend. Long story short We had a night out on the town and she invited a group of friends all females but one of her friends is (27f)BI. her bi friend comes back with us to the hotel and we all have a 3 sum that night. My gf has never been with another girl before and was always curious. Since this happen my gf is planning on staying the night with that friend next weekend for one night with my permission. We do have future plans in place were we all get together for another night of fun. I love my gf and I support her in exploring her sexuality. I like to say we have strong communication skills and she pretty much gave me the power if I’m not comfortable at any point I can push the eject button and her exploration ends. My gf pretty made me as comfortable as possible with reassuring me to let explore her sexuality and to let her stay the night with her.

But I’m ok with her staying with her one night and all but what not to say I will be thinking of my gf in bed with another person. While im at home. What are some Things I can do to prepare myself mentally ?

Thanks in advance