Howdy BDP! Question here, not a problem.

I consider myself fairly educated on vaginas- the standard clotoris, urethra, tight muscle at the opening, the cirvix inside, the way a G spot often feels inside with fingers.

Brief bio- mid 40s, married/monogamous for over 20 years, more recently enjoying ENM/swinging & playing together. So I’m experiencing new vaginas now which is fun since they’re all different and beautiful and like to be touched and fucked differently. I’m 7.5x5.6 with 6.5 head.

I’ve definitely found some tight and shallow women who need a lot of foreplay to get into and or can’t take all of me which is kinda flattering and fun but not as good as the goldilocks situation I have at home. No complaints.

Here’s my question- sometimes inside it feels like there’s a second super tight spot, maybe between the pelvic bone and cervix? What am I feeling? When getting ridden and gripping her hips last nite it almost felt like I was coming all the way out and enjoying the tightness of the initial opening going back in, but she assured me I was far from coming out & back in again with a decently long stroke. In a deeper position on top I didn’t feel it the same way and pretty easily got the ‘too deep less dick please’ so I dunno?

TLDR: in some positions there’s a 2nd very tight spot inside some women- what am I feeling?