Did Jamie Lynn Spears’ baby-daddy cheat? A woman has claimed to In Touch that Casey Aldridge was having an affair with her while his 17-year-old fiancée was pregnant.

“He totally instigated it and pursued me,” Kelli Dawson, 28, says of Casey, 19. She says they “kissed randomly” for a while but got “hot and heavy” in spring 2007 — when he was with Jamie Lynn, but, Kelli maintains, “You never knew if they were broken up or not, because it changed from day to day!”