I agree that at the moment they don't have much in common other than sexual chemistry....Can Gabi even be considered a LI? To me, she feels more like a sidefuck that's just going to ruin the relationships with the other girls. There are barely any interactions with her outside the sex scenes and she even tells the MC not to fall in love with her. I was hoping for a bit of romance with Gabi but it doesn't seem like we'll be getting any. Her path is probably gonna end badly...
With that said that "don't fall in love" is more a message to herself than it is to the MC.