Will a dummy plug interfere with my normal monitor?

This is all very stupid and it's annoying I have to even do this, but I need my media/backup PC to still function normally when the kids want to watch movies or Youtube on the TV, but I also need it to share files, recieve backups, and be able to remote in when it's on, but the TV is off.

If I get a dummy plug, does that complicate the normal use of the PC?