If it were me, I would continue my relationship with my friend, but not do things with her and her boyfriend together. They can do couples things on their own, and you can still do other things with just your friend, can't you? It's her boyfriend, not yours. No need for you to spend time with him. You can explain to your friend about not wanting to be around the boyfriend for his aggressive political views and his hassling of you. She's seen it herself, I'm sure. If she is a good friend, she probably feels pretty bad about how he treats you and it might be a relief to her too to not have to be with the two of you at the same time. Good luck.