This is probably easier said than done.
I can only say that my love of panties was well established long before I met my wife. And we met in the era of "men don't wear women's things, and we don't talk about it". Period.
My wife knows now, after 30+years of marriage, but she doesn't "understand how you can like that". Honey, I don't understand it, either. I just know I like pretty panties, the prettier and the cuter, the better. And I feel pretty when I wear panties. And for some reason, that's important to me.
I do know I'm a gentler and kinder human being when I'm wearing panties, so it's really better for everyone in my life. Whether they know or not.
Honestly, the solution that has worked for me is "date in the trans community". (I've also spent a lot of time single.) I'm not sure how well this works for people who are actually straight cis men who just like wearing panties, rather than trans people who haven't fully figured themselves out yet. Could be worth trying, though.
One thing that's applicable to everyone is to tell your potential partner as early as is reasonable. You'll probably resist doing this -- and even if you do it may go less well than it could have -- unless you first truly accept, yourself, that you wear panties, that you like them, and are going to keep wearing them.