First there is the tattoo itself. What the tattoo says, what it means, the design and feelings behind it are all something to think about. That is very important for couples. But there is also the act of getting the tattoo done as a couple. That can be just as significant.
Make sure for the meaning to be heightened in its importance that the two of you get your tattoos done together, at the same time.
They say it is the journey not just the destination that is the prize. Think about this as a couple considering a sexy tattoo, that is meant for just you two. Spend time together talking about what is important in your relationship, where you want the relationship to go, even where the relationship has been. Consider your special and private feelings for each other. These should all be factors in your decision about what kind of tattoo to get together.
Also, you should discuss where you want the tattoos placed on the body. You will want to think of locations that are intimate and personal. This is a tattoo that if it is to be kept secret should not be visible to others or at best only during most intimate times.
A secret, sexy tattoo should also be small so it is easier to conceal. Larger tattoos will be too obvious and would defeat the intended purpose.
Should you go for words or art work? Either would work. A lot will depend on what is most significant between the two of you and your relationship. Be sure to talk about this as well.
For this reason it is advised that you do not use each other's name as one of your secret, sexy tattoo ideas. Because a tattoo is permanent, it would not be pleasant to spend the rest of your life having to wear a personal tattoo bearing the name of someone that you no longer have close, intimate feelings for.