Please read and re-read what CandDinCo stated. Embedded are the values of honesty and of honor. It may seem odd to newbies to mention these values; they are constant among those who embrace the lifestyle. You will be asked for permission to be touched, kissed, and to play. Different from the vanilla world where rejection is something to be feared, in the LS it is something that is honored. This is not mere etiquette--it is the foundation of the LS.
Joining the LS involves a conscious decision to be vulnerable--but not in the way most vanillas think. Ask a vanilla what s/he thinks the LS is about, the conception almost always begins with sex with near-random partners and the vulnerability has to do with being compelled to have sex when you don't really want to. Ask an experienced LS person what s/he thinks the LS is about, the conception almost always begins with a different framework for relating to others and the vulnerability has to do with being told "no" and having to accept that decision immediately and without explanation.
That is the foundation of the LS: no one will think less of you for saying "No", no one will pressure you to say "Yes". The social grace of "No thank you" is always appreciated, but a simple "no" is sufficient.
Now here is the surprise. Once you get used to the fact that "no" is never questioned, it feels a lot safer to say "yes". This is why experienced LS people always advise newbies to discuss their boundaries and to respect their own boundaries. We know that those boundaries will likely change with time. What matters is that you (plural, as a couple) check in with one another about those shifting boundaries.
Now here is the second surprise. As those boundaries change, you will see each other through new eyes. How you respond when you see others are attracted to your partner is up to you. For those of us who remain in the LS, padoc is right on target: the attention of others will "amp up" your marital sex life in ways that keep you grinning for weeks to come.