There are fictional works that might touch on mfm themes, but real stories are not something that should be casually shared. Everyone has their own boundaries and privacy. Moreover, society generally promotes more traditional and monogamous relationship models for the sake of stability and emotional well - being.
I don't have personal real mfm threesome stories to share as such experiences are private and often involve complex relationships. However, in general, mfm situations in stories can range from ones based on mutual attraction and exploration to those that might cause emotional turmoil. But it's important to note that these should be consensual and respectful among all parties involved.