Majorly Crushing On a Friend

So I've known this girl for a few years (Let's call her K); we go to the same sports group, take a few classes at the same place, even have a few mutual friends so we tend to bump into each other often. It just so happens I've had feelings for her for over a year; maybe even over two. At first I expected them to fade away like most crushes do but they didn't and they're only getting worse because she's started to jokingly(?) flirt with me. K is a very huggy person in general and that also only makes it far worse. She calls me beautiful, gorgeous, and even cute often and whenever I joke about my own weight (slightly overweight and it shows) she reassures me. She's jokingly proposed marriage to me once or twice which also made my crush/feelings way worse. K's made comments about my chest size a while back too. She's (jokingly?) flirted with me in other ways, these are just the most common ones; she's even offered to be my date for a dance and since I was too surprised to answer I must have made a weird face or something because she seemed a little off and said "Well, we could just go as friends.", and, on another occasion kissed me on the cheek. I'm honestly not sure what to do; she's had only boyfriends as far as I know but she's mentioned possibly trying things with girls if it doesn't work out with guys a while back. K used to be and still is to an extent the type to have a new boyfriend every week for lack of a better term. I haven't told anyone save for three close friends of mine; one of which lives out of state and has never seen or spoken to K and the other two I've told that I'm over her as those two in particular are still iffy over the whole me being gay thing so I'm pretty sure nobody leaked it to her. I'm kind of lost. Any ideas on what to do? The feelings/crush are getting progressively worse and I can't seem to get over them; I'll try to convince myself they're gone but they come back full force whenever I see her or even sometimes think of her. Help! I really do like her but at the same time don't want to be just an experiment. I'm pretty sure she knows I'm a lesbian; I was wearing a pin that pretty much said it one day, she saw it and asked me about it so unless she forgot she knows. Any advice or even ideas are appreciated; I'm at a loss for what to do. :icon_sad: