A Fox News Guest seemed to have too much fun celebrating the huge military parade Saturday … slurring her speech on-air after posting a pic of champagne — though she insists she wasn’t drunk like some online have claimed.

Rebekah Koffler joined the cable TV network during the big parade meant to celebrate the U.S. Army’s 250th anniversary Saturday … and, she started on a long, rambling segment during which she seemed to slur her words.

Check out the clip … the two show hosts seem confused about what she’s saying as she stumbles through her spot on TV.

However, Koffler took aim at that assertion this morning … claiming bad actors are trying to destroy her rep — ‘cause she was clearly making a joke about the champagne.