While deep and passionate thrusting is often sublime during penetrative sex, that kind of movement can create a massive hurdle for anyone who suffers from endometriosis. Endometriosis is a disease where tissue that's supposed to grow inside the uterus actually grows outside of it and attacks the reproductive organs; when a partner accidentally hits or brushes against that tissue, it can cause enough discomfort to ruin the evening. But that doesn't mean sex is totally out of the question. It may just take some readjusting.

Before things get heated, partners should discuss positions and "be willing to experiment and make mistakes," said Irene Fehr, a sex and intimacy coach in the Netherlands.

"Understand that you're going on a journey and figuring this out together. There is no right or wrong answer," she said. "Fear of making a mistake prevents people from trying new things—and that's the only solution here."

Here are five endometriosis-friendly sex positions that you should try next time you want to turn the lights down low.

Modified doggy style

Most patients with endometriosis have an overactive pelvic floor muscle, explained Pamela Morrison Wiles, a pelvic pain expert and physical therapist in Manhattan, New York. Because people with endometriosis often have "myofascial trigger points," which are tender, sensitive areas of the pelvic floor muscle, deeper pain can be especially prevalent if you're being penetrated from behind while on all fours, she said.

If classic doggy style is too painful, lying on your stomach while your partner lies on top of you can provide stimulation and intense body-to-body contact without allowing penetration to go too deep. From the bottom, you can better control your position and the angle of entry by tilting your backside up slightly or remaining flat on the bed. That tilt also allows enough room for you to still use a toy or have your partner reach their hand around to stimulate your clitoris to increase the sensation.

Be the little spoon

For Chelsea Blackburn, an Austin, Texas-based life coach who focuses on helping women with endometriosis manage their pain, the spooning position is ideal. Blackburn, who was diagnosed with the disease in 2012 and has struggled with heavy periods and abdominal pain since 2004, when she was 15, said positions like doggy style can still cause her pain during sex.

"When that happens, my partner and I will both lay on our sides," she said, adding that the position offers her all the pleasure and benefits of being penetrated from behind, just in a much more comfortable position. Lying side by side provides an angle that isn't as direct or deep as doggy style. The person with endometriosis also has more control with thrusting. "That sideways motion doesn't hurt at all usually," she said. "So I really love it."

Getting on top

Navigating discomfort during sex can cause anxiety, but hopping on top can ensure that the person in pain can "control speed, angle and depth of penetration," Wiles said. Going slower—which may be the preferred speed for a person who is cautious of any sudden pain or discomfort—is a lot easier when you're the one in charge of the pace. It's also a way to work up to a faster rhythm without jumping right into deep thrusting. An additional perk of being on top is having easy access to your clitoris for increased pleasure.

Missionary with a hip lift

For many patients, endometrial scar tissue causes the uterus to tilt backward toward the rectum instead of toward the belly. This means that the cervix, that donut-shaped opening located at the lower part of the uterus, sits at a different position than normal; when it's bumped aggressively by a partner's penis, that can create a lot of pain. But placing a pillow under your hips during missionary sex helps elevate the pelvis and change the approach, making penetration more shallow and, therefore, less painful.

Experiment with mutual masturbation

Some of the best sex doesn't include any penetration at all. If intercourse feels too difficult during a bout with endometriosis, mutual masturbation can be a fun and pain-free solution. It opens the door to experimenting with toys to get each other off or using your hands to stimulate and satisfy each other in a different way. Masturbating in front of a partner, or watching one another, can also introduce a new type of pleasure to the relationship.

If you are in pain, don't force yourself to have sex and don't ever feel pressured by a partner to continue. There are ways to work around your discomfort. Take proper breaks or stop having sex entirely until a solution is found.

"Don't apologize for your condition," Fehr advised. "Just let them know what your body needs to feel safe and experience pleasure."