I'm guessing that you're discussing past sexual partners. Like "I slept w/this # of people etc."
Hearing that number can be an issue, but I'm also older & come from a very conservative background.
Yeah I think it can effect your psyche if that number needs to be explained somehow. Does it correlate to the persons age.

For example id have an issue hearing that a 20 yr old had 5-10 or more partners. But that's just my opinion & yes I think knowing if they practiced safe sex would make a difference to me.
Just MHO though.