Welcome to our forum.
Any chance Guy #2 will come around eventually and be okay with it? Do you have a stable dynamic set up between the two, or does Guy #2 often disrupt that dynamic? As the others have said, is this (or can it be) compatible with what you want, long-term?
I wish you the best, and hope you find Polyamory.com to be helpful.
Love means never having to say, "Put down that meat cleaver!"