Hi, I have this problem when it comes to having sex with my girlfriend. I'm not able to penetrate the whole penis into her vagina. Only the head of my penis is going in and I'm not able to push the rest of my penis into her Vagina. Her vagina is not tight, I've tried fingering her with 4 fingers and it wouldn't be a problem, but when i try to penetrate my penis it just wouldn't go in. I don't know what the problem is. She gets dry very fast and i have a small tilt when it comes to my penis towards the left. We tried cowgirl position once and it worked but later again when we tried it after few weeks it didn't. I'm really worried this would screw our relationship.