HELP ME

Ok so both me and my friend have a crush on this guy. Well it turns out that the guy has a crush on me and asked me out. I accepted but I was really worried about why my friend would think because she is the jealous type. I told her and she seemed ok with it. But lately she hasn’t been acting normal. I asked her if something was wrong and she said everything is fine but I can tell somethings not right. I don’t know what to do. I can either 1. Break up with the dude, 2. Pretend to break up with the dude but keep the relationship going and lie to my friend, or 3. Keep the relationship and lose a friend. BTW I’m still not sure that she’s even mad because she hasn’t confirmed it.