I m 18 year old and my penis secrete some creamy liquid while I m sleeping . Whats it and how to?

it's called seamen. that happens from having a wet dream most of the time. it happens to most guys once in a while. no offense, but you should know this by the time you turn 18. didn't you have sex ED in middle school and/or high school? again I'm not trying to make you feel bad, just wondering.