Me (M25) and my girlfriend (M21), we have been dating for almost a year now, and lately i have discovered this new fantasy growing inside me to watch her having fun/ fucking another guy. She has always been a great slut in bed which makes my fantasy grow even stronger. We have a really loving and intimate relationship and she has told me, she prefers monogamy while we were sharing our opinions about threesome. Even though my fetish is getting stronger each passing day, i don’t want to ruin our relationship dynamics tho - Give me advices to communicate the same with her and maybe some precautions about the whole mfm thing because It’s completely new to me.