Hear'Say snubbed Kym Marsh's wedding because of the way she left the band.
According to band member Noel Sullivan, they missed her big day because she didn't have the "decency" to tell them she was leaving.
Kym Marsh quit Hear'Say in January and married EastEnders star Jack Ryder earlier this month.
Hear'Say's Myleene Klass told this month's edition of CD:UK magazine: "Basically, this is what happened with Kym: One day everything was fine. Four days later management rang to say she'd left!."
Fellow band member Noel Sullivan said "If someone hasn't got the decency to tell you they're quitting, why would you go to their wedding? And she hasn't been in touch since she left."
The band also took the opportunity to allay the rumoured tension between themselves and Liberty X.
Danny Foster said: "There's no trouble with Liberty X. People shouldn't try to put us against each other, it's all good. Our goals are different from Liberty X's anyway."
Noel added: "There are a lot of bands who've had a chance to come up while we were out of the way. I say congratulations to them all - it's never been about competition between bands."
The September issue of CD:UK magazine is out on August 23.