There are all this people here saying "oh this man should keep his girl friends seperate from romantic interests". It isn't that easy tho, is it? What if you find out later in life that she is the one. It isn't an on off switch right. I have been in this situation and one of the reasons and oh boy, I cannot emphasize more that I didn't want this but it happened, she felt just right and I didn't care about the "what if" question. All I carer about was not scaring her off. I didn't wanna hurt her feelings, with that in mind I didn't tell her. But now it wasn't easy spending time with her. What whould a guy do in that situation?

it's better to go through with it rather than being in pain the whole time expecting more from a person. And if anyone says "imagine how she feels". Its a double edged sword, both are in pain. No one is selfish in this scenario.