Megan Fox and Machine Gun Kelly are "very excited" to welcome their first baby together, a source exclusively tells PEOPLE. "They can't stop talking about the baby," the insider says.

Parenthood isn’t a new role for either star. MGK, for his part, is father to 15-year-old daughter Casie, whom he shares with ex Emma Cannon. Meanwhile, Fox shares sons Noah, 11, Bodhi, 9, and Journey, 7, with ex-husband Brian Austin Green. (Green, for his part, has moved on with fiancée Sharna Burgess, with whom he shares 2-year-old son Zane.)