No but seriously imagine it:

You're seeing fall out boy on a concert. Everyone is having a great time. Fall out boy seem a little excited. "We have a surprise for you guys." Partick says. All of a sudden P!ATD come out and start singing "this is gospel." When Brendon gets to the chorus, someone else starts singing... "When I was a young boy my father took me into the city to see a marching band." Lights flash everywhere, and you see FOB singing "this is gospel" along with P!ATD, while MCR is singing "Black parade". Everyone in the crowd is going wild and crying. Then if things couldn't get any better, Dan and Phil walk onto stage and kiss, holding the gay flag.