1. Hold hands: it is important that your children know that you love each other, and it is important to show them that love through physical displays of affection. Holding hands while walking, watching movies, and driving is a simple way to show your family, and others of your affection and love for one another. Holding hands also helps your relationship. Children who see their parent's holding hands have a bigger security net. Children need to feel safe and secure. Most children have friends whose parents are divorced, and most children worry about, and wonder what would happen to them if you and your husband got divorced. So, hold hands regularly, and they will not worry about it as much.
2. Hug: giving your spouse embraces and hugs is an important part of displaying affection, and it is an appropriate form of affection in front of children. Children know that hugging displays love and respect when they see their parents hug goodbye. These hugs should be embraces, not full body contact where you are pressed up against one another. That is an inappropriate form of affection. Basically, think of hugging the way you would want your child to hug their boyfriend or girlfriend in front of you.
3. Kiss (peck): it is important for children to witness their parent's displaying deeper commitments of love than hand holding and hugging. A kiss is a form of this deeper commitment, and your children should see you kiss frequently. You should be kissing one another good bye when you leave for work, and good night, etc. However, a kiss is a singular word. You should not be making out in front of your children. If it would be inappropriate at work, it is probably inappropriate in front of your children. Small pecks, and brief lip locks are the types of kisses your children should witness. Younger children really pick up on what they see, and you do not want your 2 year old slipping you some tongue next time you kiss him goodnight, so don't kiss one another that way in front of your child.
4. Pinch butt: one last form of affection that many agree is appropriate in front of children is the butt pinch. Yes, it is true. So, why is this appropriate, and important? A butt pinch shows your child that the romance is still alive, without actually showing them much romance. It is important for your children to know that you still find one another attractive, and that you choose to flirt with your spouse. This will help your child create better and more appropriate relationships.

If you can learn what displays of affection are appropriate in front of your children, and most importantly, which ones are not, you will raise children who feel secure and loved, and know how to engage in appropriate physical relationships as they begin dating and expressing feelings for the opposite sex through physicality. When in doubt, simply ask your child what they are comfortable with, and be sure to never embarrass them by your PDA, by being too affectionate in front of their friends.