If broo meet something then generally then will infect it, screw it, kill it or eat it.
In your situation, the spring virgin is out of bounds for all those, except maybe infecting her. So, what's an up and coming broo to do? Take his frustration out on other people. Either people they meet, livestock they come across or each other.
Failing that, what is the penalty for deliberately failing the mission?
Bad for the clan? Broo don't normally care.
Their turn in the barrel? Depends on how graphic the game is.
Public Castration? A definite option.
Ripped apart by other broo? Another favourite.
If the broo don't have an idea of what will happen to them if they don't complete the mission, then they probably won't complete the mission.
As for broo being comic relief, they are in a way. Bear with me here. On the one hand, they are vicious, infectious rapists, who can turn a game around into a very dark place simply by being involved in the scenario. On the other hand, they can be dangerous threats who are always thwarted at the last minute.
Just, don't, don't, don't have the spring maiden as a PC.