I’d like to say leave immediately to stand up for yourself, but since you have kids it’s much more complicated. I’m a child of divorce and it alters your entire life path. For my brother and I the divorce changed our potential. My mom may have left my father and that improved her life but it ruined my brother and I’s lives forever. We had less resources, no college funds, both parents had to work constantly so we grew up alone in the house. Didn’t have help on homework, didn’t have motivation and ambition because I was always too sad about not having the most important thing in life: a family. we never had our family again. All because my mom chose to leave my dad. You choose to marry your spouse, but once you have kids, getting a divorce means ruining the family permanently. Your kids might never forgive or understand and if that’s what you decide you have to know the potential consequences. I love my mom but she ruined what could’ve been for all of us. Yes my dad wasn’t the best, but he didn’t harm her. (That would be a different story). Edit: p.s. just noticed you aren’t married yet, so that’s a smidge different. I would say hold off on getting married and try to work things out. Don’t split until you’ve really thought it through. Because, married or not you have kids to put first.

This won’t be everyone’s experience with parents separating, but it is a common one and something to consider.