I can only say this if it can help.
Don't take it personally ! I know that's easier to say than do, but if you think about it, even from your own experiences, sexual chemistry is a funny thing.
There's a lot of variables that go into what turns us on. It's not all about looks etc. A lot of it has to do with people's sexual outlook which is something I think you pick up/feel rather than see or discuss. And from what I've seen it's pretty hard to make oneself into a different sexual being than we really are by nature. People try I know, with some limited success, but when the truth comes out it seems the effort usually fails. Neither party is fully comfortable knowing it's almost a form of acting and it seems everyone really wants sex to be real !
The other side of the equation is that many people repress their true sexual being for fear of disapproval by a (potential) lover. So it's easy for someone to read the signals we are trying to send (let's say a little conservative) when in reality we'd love to have someone discover the tiger in us. So what you ' see' is not necessarily what you may be getting in the end.
I guess this is why I always try to start an open discussion really early on about sexual desires & preferences. To avoid just such scenarios as this ! I don't want to end up hurting someone's feelings over sexual differences.
All of this says nothing about who you are as a person. People's sexual appetites vary as much as their culinary appetites. It's just part of who we are. We're not going to want to spend a lot of time dining with someone who eats primarily seafood if we abhor seafood. The best we could hope for is opportunities where we could find a varied menu where we both could have choices we enjoyed best.
If you're thinking this is a big part of what poly is about...........well.........
I'd suggest letting it go (the sexual thing) for now, but dig deeper, including into yourself, to see what some of the true preferences might be and which ones may have been masked. It happens that people make some very interesting discoveries that run counter to what first impressions were.