did I lose my chance with him after telling him this?
Most Helpful Guy
Well, it depends on why you told him. If you are sharing about yourself, opening up and to reveal things about you may sometimes require you to talk about previous relationships that's fine. To get close to someone you need to share things about yourself and life shaping events.
If you just want to do a checklist and go through people you've dated and such, in that case you may just wait for him to ask you about such things and if he never asks you might not bring it up.
Most Helpful Girl
Depends on the guy. Though if someone is gonna think you're a whore because of your previous sexual partners, the number of them, or the nature of your sexuality, run and don't look back. Newsflash: women are autonomous sexual beings, having sex and exploring your sexuality is not a negative thing provided you do it with respect for everyone's boundaries. No need to waste your time on people who think being sexually active makes you somehow a shitty person.
Personally, I like to talk about my exes and hear about my partner's, because they are part of the history and experiences that have shaped us as people and like any past situation or experience, they can offer insight and information about who we are, what we like and dislike, the baggage we carry,... Being open and honest should never be a bad thing and if someone takes offense to that, they need to sort their issues.
(We're not talking making your partner feel shit by comparing them to how your ex was better or what not, but that's literally not the same as just sharing your past experiences. That's being petty and deliberately hurtful)