This is a lot of "new" that you are all sorting out. It's only been a week. There's no way you're going to have all the answers yet about where this is going to go. Your love interest's bf has a lot to process. I doubt he knows for sure yet that he'd never be ok with you being physical with your love interest but for now it feels safe to him to say that he'll never be comfortable with it so that he doesn't get pushed to move faster than he's ready for.
When you're one of the people who's involved in NRE every little step seems to take forever because you know where you want to be. For those on the outside of that NRE I assure you that time seems to be moving much faster and that it seems impossible to keep up with all the changes that have (from thier point of view) come out of nowhere.
Give it some time, go with the flow and enjoy this new relationship for what it is now, without any expectation of what it might become down the line. Build a relationship with her, keep talking to her and her boyfriend. Things might shift slowly but chances are that they will shift. There isn't any rush, if it's supposed to be it will be. If it isn't supposed to be you have learned that you are biromatic which is an important peice to learning who you are as a whole.
Everything will be ok in the end. If it's not ok it's not the end.