Don't know if this is a case for everyone else or maybe the authors just doesn't have experience, as far as I know and base on my experience if a woman is really turned on it won't tighten up instead it will be much more loose and the D will go way deeper. Welp I haven't met many so I can't really tell about pthers
so by tight i think they mean she’s flexing aka tightning the muscles inside which women can do either involuntarily or voluntarily sometimes it’s just a spasm from the stimulation or it’s them flexing it on purpose!
Don't know if this is a case for everyone else or maybe the authors just doesn't have experience, as far as I know and base on my experience if a woman is really turned on it won't tighten up instead it will be much more loose and the D will go way deeper. Welp I haven't met many so I can't really tell about pthers