How do you tell Your best friend you have feelings..

My best friend and I have been friends since high school, moved into the same apartment complex so we were literally across the complex from each other now we live on opposite side of town. We will see each other a few days a week and I go spend the night at her house or she comes to mine every weekend. We both like both genders. Lately I’ve been feeling some type of way about her! Like I’ve always found her really attractive but lately it’s been more. Anyways, we always drink on weekends together and play board games, movies, food ect and last night we played the game called Incoherent. One of the cards I had to guess was “sexual tension” and she gave me her own hint as “something I’m feeling right now” and the rest of the night when we looked at each other it was different like there was a lot of sexual tension between us. Like when our eyes locked it just felt different. I’m not sure how to bring it up to her that I have feelings for her and don’t want it to seem awkward. Any tips?