Does sex hurt sometimes? It's a lot more common than you'd think.
There are tons of reasons why penetration can be painful, but one of the usual suspects is tension or shortened muscles of the pelvic floor. Muscles that are asked to stretch or elongate when they are unable to... hurt! Ever tried to do the splits when you've never done it before? Yowtch! Same concept applies to your pelvic floor. If we've got a lot of tension down there and we try to accommodate a finger or a penis, etc... well, you know the rest.
But the good thing is that by identifying where some of these tensions are, you can position the muscle so it might not get as much stretch or tension—and decrease the pain. No one should ever have to just grin and bear it through sex, and seeing a physical therapist or a specialized gynecologist should always be seen to rule anything thing else out. But by trying some of these positions and tips, you may be able to ease the discomfort with intimacy while working through elongating the muscles to address the underlying condition.
This video can also help provide positioning options for people with c-section scars, or pregnancy or postpartum-related pains.