At the end of the day, you're in control of your actions. You can catch feelings with as many people as you'd like but the only thing that really matters is which one of them you've put in the work with, and who you're willing to do the hard work of building a relationship with.

If your girlfriend is the most important person in the world to you, you don't have anything else to worry about. I wouldn't pass up a job I was excited for over something like this.

On the inverse - are you maybe having these thoughts because you're not as secure in your relationship as you should be? It's something to consider. You might find that you have repressed feelings that are unresolved, or you might become even more confident in your current relationship.