Couple walks into drug store looking for lube, employee comes up and asks if they need help.
The couple needs help deciding which lube to purchase. Guy asks if they can try them out, and the employee says of course.
Couple starts having sex in various places through out the store that aren't visible but you get the idea. The girlfriend says the competitors lube does not last long enough.
The couple try a different lube and more to a different sex position, the couple agrees that the competitors lube is too watered down. The couple really wants to find the perfect lube and the employee asks if the need any assistance.
The Employee recommends Trojan so they try it out.
They then come to a mutual agreement that Trojan is the best lube