you have just created a paradox where there was never a reason for him to travel back in time to stop himself from travelling back in time, therefore this version of either one now no longer exists and the girls will not be thanked.
If we change the past, it could affect the future; great insight, we shouldn't be using this; And so then they told me so I traveled back in time to stop you from ever time travelling in the first place; Whoa, I never thought about it like that before. Can you thank those girls for me, future me?