I agree with stranger. It's understandable that since you live together things might get "weird" if you get together but that's just a part of life. If things work out then great if not then so be it. If you really don't feel comfortable with the whole situation then just talk to her. You both are practically adult so there's no reason you can't talk and figure this out. But really you should go for it, you'll never know what will be until you give it a shot. Don't want to be asking yourself in 5 years "What if" right.