geecrizz...
She told me she was naturally curious about him anyway.  They did have a connection beyond just sex, he was a double of me basically, just a dominant version.  The sexual tension was there, it just needed a kick start.  Which I conveniently provided for them, the first time they were intimate.  I do have a thread where I went through the process from start to end...  
https://www.cuckoldplace.com/36_60320_1.html"StupidCuckBitch : If you are okay with a link to my old thread, great... if not please let me know and I will delete it. "
She last couple of time they fucked, they both kinda felt guilty after because he had a steady gf, and it was a dedicated relationship where we all became friends.  At this point she expressed no interest and sometimes get pissy when I suggest it.  She says never again.  So to be honest, I don't ever seeing it happen again.  
I love seeing/hearing others who go from wannabe, to full cuckold.   
She later felt guilt for "cheating on me"