Dog the Bounty Hunter's set to get remarried next week, but when he does 2 of his daughters will not be sitting by his side ... 'cause they're not on the guest list.
Cecily and Bonnie Chapman tell TMZ ... their father did not invite either of them to his September 2 wedding ceremony -- where he'll be getting hitched to Francie Frane -- and they claim not to know exactly why he's snubbing them.
Both women say they have no ill will toward Francie and are perfectly fine with their father getting remarried... so they speculate it might be a personal issue with Dog.
Cecily -- who's actually Dog's stepdaughter -- thinks she and Bonnie may remind him a little bit too much of their mom, Beth... Dog's late wife, who died in 2019 of throat cancer.
Cecily says she and her sister certainly resemble Beth and their lives are similar to hers ... and she thinks this scares their dad, so much that it may be the reason for no invite.
What's interesting is Garry, like Bonnie, is the biological child of Beth and Dog ... but he DID get an invite to the wedding. The girls think it's because he doesn't resemble Beth, and Dog tends to favor his sons anyway.
Cecily adds she reached out to her dad about not getting invited via text, but never got a response. Bonnie has not confronted him, but makes it clear she thinks she should be at the wedding ... and Beth would have wanted it that way too.
Dog and Francie tell TMZ ... "We love Cecily and Bonnie very much, as we do all of our family. We pray for their health and happiness every day. Beyond this statement, we wish to keep any family issues private."