You are getting some hard advice/comments from HN'ers.
So, you might feel like you are "in love" with her, but are you really just in love with, perhaps, her work ethic, devotion to the startup, the fact you are probably spending a lot of time with her, etc?
Maybe you just haven't found these traits in the right girl yet? I think you really want a girl in your life that has these traits.
Don't cheat on your best friend with his girlfriend. It is bad for the friendship, bad for the company and you don't know what hole this might leave the guy with. You may effect his trust level in everyone for a long time to come. I myself could not live with having done that.
So, you might feel like you are "in love" with her, but are you really just in love with, perhaps, her work ethic, devotion to the startup, the fact you are probably spending a lot of time with her, etc?
Maybe you just haven't found these traits in the right girl yet? I think you really want a girl in your life that has these traits.
Don't cheat on your best friend with his girlfriend. It is bad for the friendship, bad for the company and you don't know what hole this might leave the guy with. You may effect his trust level in everyone for a long time to come. I myself could not live with having done that.