Sex in the water is often a way to beat the bedroom boredom and add some spice into sex life. However, not all the water adventures end up in sexual bliss for couples. Sex in the bath can be tricky enough and you should be prepared to face certain discomfort.
Stay wet

First of all, in spite of the fact that you won't have lack of moisture in the bathroom, your body will be dry in the most intimate zones. In fact, water washes away all the natural lubrication, making penetration less comfortable. The gentle tissue of the vagina can become irritated and together with other chemicals like bubble bath, soap and oils it may cause some irritation and make you more susceptible to thrush.

So if you want to stay lubricated during water fun, it is better to use some lubricant that is not water-soluble like silicone lubricant.
Make it a safe place

Bath tube can be not suitable for sex fun as the surface is quite slippery to perform water sex just like the movies show it.

Make sure you have some support to have sex with your partner. Standing position is quite common in the bathroom though may require some maneuverability. Having sex in missionary and doggy style positions can also be not quite smooth.

You may consider having oral sex as in this case, you will be more in control of the situation.
Make it more sensually-oriented

If having sex in the bath has proved to be uncomfortable, you can reserve your bathroom for foreplay. You can gently rub your lover's back and chest with soap foam, give sensual strokes and enjoy the aroma oils to create sexy mood.

It is also good to start any sex play in the bathroom since you will be sure that both of you are fresh and clean to fulfill your naughtiest fantasies later in the bedroom.
Think about contraception

Many people think that they cannot get pregnant in the water. This is a myth. Do not believe that hot temperature of the water will kill sperm or prevent sperm from fertilizing the egg. Also sex in the water does not prevent STDs. Condom is an effective method of contraception, but using it in the water can be quite problematic as it can slip off.

If you are not sure about safer sex in the water, it is better to move on to the bedroom where you can be more confident in using a reliable contraceptive method.