Tony! Toni! Toné! -- Divorce! Divorce! Divorce!

It feels good ... to be married to Tony! Toni! Toné! member D'wayne Wiggins ... but only for a dozen years or so, at least according to his soon-to-be ex-wife.

TMZ has learned ... Michelle Lochin-Wiggins has filed for divorce from her husband of 12 years, and is seeking custody of their two teen boys, ages 17 and 14.

In the docs, Michelle cites irreconcilable differences with the 50-year-old singer, who sang and played guitar for the '90s R&B group.

While her request for full legal and physical custody signals that all's not well, she does plan to offer D'wayne visitation rights to the kids.

Oddly enough, neither is named Tony, Toni or Toné.