is your wife able to penetrate herself manually? she may be nervous and therefore her PC muscles will be tightened. the first few times you have sex it may be difficult but the more relaxed she becomes the easier it should be for you to penetrate her.
Best of Luck!
~S.A.
her pelvic bone has shifted, see an Urologist & get x-rays. my ex doctor told me to try different positions. my new doc took x-rays and told me about my pelvis. my sex life was never a problem til now. i don't know if your wife has had any operations lately, i feel that they didn't put me back right. when my husband tries to enter it feels like he's hitting a bone. the pain is excruciating.. check it out with a Urologist. that's my next step. I feel for you & your wife. just remember its not you or her fault.
IN THE SAME BOAT
You might try using vibrator to get her started stretching out. Just start slow and use lots of lubrication.
i guess your wife is still virgin and it's always hard to have sex(penetrate) for the first time. it will be fine if u keep doing sex...