Article continues below advertisementJason Kelce is beyond ecstatic about Taylor Swift officially becoming his sister-in-law.The older brother of Travis Kelce reacted to his younger sibling getting down on one knee during the Wednesday, August 27, episode of the duo's "New Heights" podcast."Before we get to the [episode], there is one gigantic piece of new news that just hit the waves," Jason declared just hours after Taylor and Travis revealed their engagement via Instagram on Tuesday, August 26.