Sex and relationship expert, Dr. Trina Read, is ready to answer your questions.

I’m in my 30s and have trouble feeling confident with my size. I think it may be affecting my marriage. Any help?

Research shows that penis size does not affect a partner’s sexual satisfaction. However, I do appreciate that A LOT of guys wish they had a bigger penis.

The average erect penis size is five to seven inches. If you’re a little smaller, it isn’t a deal breaker. So... instead of focusing on your penis size, you’re better served focusing on her sexual pleasure.

Crash course on women’s sexual anatomy: The clitoris is external and all women can orgasm through clitoral stimulation.

The average vaginal canal is about six inches deep. If your penis is longer than her vaginal canal, you’ll hit her cervix—women find this irritating and uncomfortable.

The first two inches of a gal’s vagina is the most sensitive, as this is where all the nerve endings are. The last four inches have barely any nerve endings.

Her G-Spot can be anywhere from the top of the vaginal opening to about 2 inches back. You only need a two-incher to do the trick.

Great Sex Tip: Sex is important, but most women prefer a nice guy. Focus on your skills as a partner rather than the size of your member.

I am interested in introducing some light bondage to my marriage. How can I do this without freaking her out?

Bondage is the use of physical restraints during sex to enhance sexual pleasure: like having a silk tie or scarf wrapped around wrists or ankles.

According to several studies, approximately half of both men and women have experimented with some type of bondage activity. However, the word "bondage" does seem to freak some people out. Perhaps it’s better to use term like "a little tie up," which is more palatable.

Here are a few good ideas to introduce the idea of bondage: Don’t bring it up or surprise her during the act. The best time for discussion is to sit down with your wife during everyday activities like when you’re having dinner or watching TV.

An easy way to approach the topic is by prefacing with, "Hey, I read an interesting article the other day" or, "Guess what so-and-so told me?"

Respect your wife’s wishes if she’s not comfortable sharing this activity with you. She might just change her mind a few months from now.

Great Sex Tip: The same endorphins released for pain management are the same endorphins we experience during orgasm; which is why a light spank while being tied up can enhance sexual pleasure.

Dr. Trina Read is the founder of Business of Sex, a marketing company that helps adult product companies and sex educators market and monetize their business. Trina has a degree in business, a doctorate in sexology, and is a leading relationship and sexual health expert and educator; a best selling author, media expert, syndicated blogger, international speaker, magazine columnist, and spokeswoman. Follow her on Twitter.