'Mormon Wives' Stars Mikayla Matthews and Jace Terry Separate

'Mormon Wives' stars Mikayla Matthews and Jace Terry have split ... and it sounds like their bedroom chemistry, or lack thereof, is to blame.

Mikayla and Jace revealed their split in the newest season of "The Secret Wives of Mormon Wives."

The separation comes amid intimacy issues between Mikayla and Jace ... she was sexually abused during her childhood and says kissing is a trigger for her.

Jace tries to get Mikayla to do trauma therapy, but she tells him she's "already maxed out" and her "bucket is full" ... and she packs her things and leaves in a dramatic scene.

Mikayla tells Jace she wants to work on herself outside of her responsibilities as his wife ... and while she leaves the door open on getting back together, Jace tells her they should stay separated until she feels that she can commit to their relationship.

She tells Jace she thinks it's better for their kids if they can work things out ... and Jace shoots back that he wants their kids to "see their parents having a good, intimate connection and emotional connection."