Is it normal?😞

Im 16 and been in a relationship for about a year and so far it is going really great, yet we fight almost alot.. But then i started developing a huge crush on a guy i been friends with and i feel extremely bad. I never flirted with him nor will i ever do that. Im 100% faithful, but is it normal for me to have a crush on someone else? It most likely will go away, hopefully..