Crush

Hi! I am doing my PhD now. Unfortunately I have developed feelings for a colleague now. He is a very sweet guy and fun to be around. He’s open to me venting out all my problems at the end of the day without being irritated. He even asked me out twice and he have gone out for walks together. But we work in the same team. Plus there are cultural differences between us. I know if I go to him I’ll get rejected either way because we have a professional relationship and I am scared that if anyone gets to know about my feelings, I’ll probably be kicked out of my team. What should I do here?