Trait: Tribadism on Penis
This is a sexual act involving one man and two women. The women rub their vulvas together with the man's penis between them. The man may also take a more active role by thrusting his penis between their vulvas or by penetrating either of the women (or both of them alternately).
Apply this trait to the character having their penis rubbed. Apply i1134 to the characters rubbing their vulvas on this character's penis.
Example 2, Example 3 - Different position.