Me and my boyfriend tried to have sex the other night and for some reason I could not get wet. I have been under a lot of stress could this be the reason?

If this was just a one time thing I would not worry about it. There are times when the juices just don't flow but this is no reason not to have sex when you are not getting wet, you can always use some of the things made for this purpose. Just remember to use more if this is an all nighter.

Stress would be the reason.

Then again, it is possible that there was insufficient foreplay before penetration.

Have you had sex before?

Stress, exhaustion or feeling distracted could play into it. Sometimes you can feel a difference in lubrication depending on where you are in your monthly cycle. Some women just get wetter than others. If you think you might be in the normal to dryer range in general, I imagine you might feel a little dryer sometimes. As has been stated, extra foreplay could help, and lubrication could be used as a back up plan. If this is not a regular occurrence, I'm sure you have nothing to worry about.

Exactly... as was mentioned a woman is not a light... you don't flip a switch and she's ready to go. Look at it like starting a campfire without a liquid accelerant or matches. You start with a spark and build until you have a raging fire.