Remember that it’s normal to feel some discomfort or even slight pain because it’s your first time (just like with first-time vaginal sex) though if you’re in a great deal of pain or feel very uncomfortable, ask your partner to stop immediately. Once your partner has inserted the tip of his penis, ask him to slowly penetrate your anus further, but at a gentle pace that you feel comfortable with.
This means it could take anywhere from 30 seconds to five minutes before his penis is fully inserted.
Breathing deeply and talking him through what you’re feeling will help keep you both stay relaxed.
Continue like this until his penis is fully submerged. Once his penis is fully inserted, the key to great anal sex varying the angle, depth, and speed of thrusting and gradually building up momentum.
My post Anal Sex from a Female Perspective describes what anal sex feels like for a woman.
If you want to try anal sex with your wife or girlfriend, but are uncertain of her reaction, use the approach I recommend in How to Make Her Want Anal Sex.
Missionary position (man on top, woman on bottom) allows the woman to fully relax her anus, making penetration much easier.
Always go very slowly and be sure she remains relaxed.
Don’t forget to use lube on each finger you insert. Choosing the best position may make the difference between a painful or pleasurable experience.
Gently stretch her anus by pushing outward on her anal ring, as if it was the center of a clock face, pressing out towards 1, 2, 3 o’clock, etc.
Once she has learned to enjoy the insertion of a single finger, try inserting a second.