When a almost-dating couple drags three of their friends to "hang out", which really means the three non-dating friends get to just sit and watch the couple deep in conversation with eachother.
Other activities can be long hours at a bookstore, and being serenaded at a park by musical homeless (but talented) men. The two have their date on the backs of three poor, bored to death friends, equalling 5(pent)people.
Tridate, aka thrid wheel, also sucks, as well as quada-date.
"hey Brit and Brad, i am so sick of hanging at this bookstore for 3 hours while Mark and Marsha discuss the meaning of Neo-commercialism in the post-pseudo-elitist world. I feel like i am on a penta-date"- Shayna