A threesome.... the most common sexual fantasy!!
FFM, is most likely the most common, but there are also MMF, FFF and MMM. However MMM excludes me, so we'll skip that one.
Lesbian sex, is one a huge turn on for most, but it's supposed to be, it is intended to inspire and broaden their sexual horizons.
Sexual acts can include, vagina, anal and oral sex along with mutual masturbation.
In order to have a successful threesome you must take care of a few things;
Make sure everyone is a willing participant and comfortable with what is about to happen
Establish boundaries (not all females want a lesbian experience and not everyone wants something near their A-hole)
Realistic expectations (A lot of things happen in movies that don't happen in real life)
I definitely enjoy the occasional extra addition in my rendezvous, however, I do not always have a partner available. In that case, should you have someone in mind, they must be approved by me first. And vise versa, if this person is not a provider they must complete my screening.