Taylor Swift and Travis Kelce Reportedly Invited Her Ex Harry Styles to Wedding

Taylor Swift and Travis Kelce apparently don't have a "no exes at the wedding" rule ... because Harry Styles got the invite ... even though he had to shake it off.

According to a new report from Variety ... the pair invited the British pop star to their mega event this weekend in New York City ... but Harry won't be there.

The outlet says Harry is too busy on his "Together, Together" tour to swing by the wedding festivities ... he's scheduled to play shows in London at Wembley Stadium this weekend with special guest Shania Twain.

While Harry can't make it, Variety reports his better half -- fiancée Zoë Kravitz -- will attend ... she's a longtime pal of Taylor's.

Remember ... Taylor and Harry dated way back in late 2012 and early 2013. Though it only lasted a few months, Harry is reportedly the inspiration behind the track "Out of the Woods," so clearly he made enough of an impression on the pop star.

As you know ... Taylor wedding updates have kicked into high gear -- food is being delivered to Madison Square Garden, a castle has already been erected in the venue and suspected guests are arriving en masse, including San Francisco 49ers tight end George Kittle.

An intimate event is scheduled for this evening ... while the wedding bash tomorrow reportedly kicks off with cocktail hour at 4 PM ET. Sources tell the outlet the 1,000-person party is set to go until as late as 4 AM.