Came is the past tense of come, which means to move toward something (and various other things). It is not, however, the past tense of cum. The past tense of cum is cummed. Look at the word hang. When you hang somebody (as in a form of execution), you hanged them, not hung them. Same goes for cum. It is a different word and meaning so it is cum, cummed, cumming, will cum, et cetera.
I came over to Erin's house last night and played video games.