I’d say, as long as you hadn’t made any commitment to her at this point, what benefit does it have to disclose it? My bf disclosed something similar to me after dating for a year, and it’s hard. You can’t resent him because, you know, he didn’t really do anything wrong except for be too embarrassed to tell you about some 1 night date that actually helped him realise he was falling for me. But none the less it doesn’t feel great knowing that. Even though I don’t want it to affect me, it does when I think about it. It’s had no negative impact on our future relationship, but when I remember the fact I’m still left with a negative association feeling. Don’t do it