I think you are asking if YOUR viewing history could be seen by someone else. Assuming you login to youtube with an account, then only devices logged in with that account would see your history.
Yes ofcourse!as ur wifi IP address will be same.but its nothing to worry about this issue as only 1% chances are there..if you are watching any videos multiple times for more than a hour.That too only just links will be seen by the same IP address but the opp person will never come to know abt this who watched it.Even it may disappear as soon as new video update.Hence no issues.
I think you are asking if YOUR viewing history could be seen by someone else. Assuming you login to youtube with an account, then only devices logged in with that account would see your history.
I've seen people talk to themselves, but not often online in a forum thread. My first though is to delete this but I am very curious about it and hoping there will be some follow up from the OP.