It can get very hot and heavy very fast during a threesome, but make sure that you stick to the rules you've drawn up. For instance, don't penetrate if you're not supposed to just because you're all revved up. Show your partner the respect that (s)he deserves.

Remember, some heavy emotions are at play here. It is extremely easy for feelings of jealousy, inadequacy and resentment to rise to the surface.

Here's a helpful hint: even if you've both decided that something like kissing is OK beforehand -- it never hurts to ask your partner if it's OK during the act. It'll feel empowering to them and it will let you know that everything is cool.

The Act
A threesome is not just sex with an extra person. The whole rhythm of it is completely different. You'll find that it happens more as a "cycle" rather than the "back and forth" of regular sex. The trick is to relax and enjoy it if the other two people are more engaged than you at a particular moment. During a three-way, the focus tends to gradually shift from person to person.

The Aftermath
This may sound harsh but once you've done it and everyone is satisfied and you've laid around for a while, get the third person out of the house. You're not building an emotional relationship with them, so having them sleep in the same bed as you and your partner is a big no-no.

Also, let your partner know how much you enjoyed seeing them turned on. Basically, allow them to see that they are your first priority and that while the act of the threesome is tons of fun, there's no one else for you but them.

And hey! Let's be careful out there...