Trio sex is sex with three persons.
When you have sex with three persons you basically do the same things as when you are with two people: kissing, caressing, oral sex, stroking the genitals and having intercourse.
All three can be active at the same time or two can have sex while the third person watches the other two. After a while you switch roles.
Many people fantasize about trio sex. Although this can be exciting, in reality it’s rather complicated. It may difficult to gear all activities to one another. Often one of the three feels left out.
Trio sex has more to do with lust than with love. If a couple tries trio sex within their relationship it can turn out differently than expected. Jealousy easily pops up. It becomes really complicated if one doesn’t want to repeat it while the other two want to have trio sex more often.