Those old-school thick condoms maybe, But If she's very wet she'd never tell. It's like when a condom breaks neither of us notices until afterwards, especially with these ultra-thin condoms. In that case, she didn't feel a difference and neither did I. Would probably be near impossible to tell. Unless I pulled out and visually saw.
Guess it depends on the person because sex with a condom for me is very different from raw. To the point where when birth control started fukking with my wife i hurried up and got snipped because condom sex is wack.