“These violent delights have violent ends, And in their triumph die like fire and powder, Which as they kiss consume”

The violent delights part of the text is referring to Romeo and Juliet’s love because its fast, unpredictable, passionate, uncontrollable and also could be potentially damaging to not only just them but both of their housholds. The ‘violent ends’ is talking about how both of their deaths are painful emotionally and physically. The second line talks about their ‘triumph’ dying, I think this is hinting about the fact that at this point their only way to be together and win is to be together in death. The final line signifies that their love and passion is going to end up killing (consuming) them.