Not without hurting a lot of people in the process. While it is natural to want to avoid hurting others, avoiding uncomfortable conversations that may save all parties from more pain later is an important consideration to make. Avoiding confrontations will become a pattern that will continue to play in other aspects of your relationships as well.
There's nothing wrong to have feelings for anyone. Just be true to yourself and your girlfriend. Let her know about your feelings for your bestfriend. This will make her sad for sometime but eventually she will understand and will respect you for your honesty.
If you know what’s the meaning of loyalty then you do know what you have to do!
You can avoid all these fuck ups by making your girlfriend and best friend good friends, and the talks for both of them can be different, you should know when to draw the line.
The sooner you clear things up, the better. It'll get more difficult with time.
Honesty is the best policy when it comes to relationships! I'm speaking out of my experience. More than anyone else you are making yourself suffer by being in a relationship when you feel for someone else.. Don't put yourself through that agony. You might not want to break your gfs heart by avoiding telling her that you feel for someone else but believe me she will appreciate that more than you hiding it from her. At the end of the day you're doing this for her but she won't even appreciate it if she finds it out. You rather be honest, think about your relationship, discuss it with your best friend and take a call.