Is it normal to be this turned on when another man touched my girlfriend?

I have told my girlfriend about my fantasy to watch her have sex, I just think the way she moans is so hot, I think she would moan even louder knowing another man is in her while im watching, she would feel naughty making her real excited... Well her friend came to visit her and i had told he she can have a guilt free weekend, she wasnt sure to believe me so i encoureged her to have some *fun* very strongly. Well he came up two weeks before planned being a suprise, i wasnt sure if she would do anything this early not being prepaired for it, but than she texted me later and said he whispered in her ear that he wanted to finger her, so now that i told her she could, she let him... well that turned me on so freakin much, I am really impatient waiting to hear more, i hope they went all the way, i want to know all about it, im so turned on to the thought of my girlfriend having sex with another man at this very moment, i just wish i could be there... but maybe next time? ;) I just cant wait till i get to see her again now, im going to show her how happy i am with her!