More poor you. Since DS is an adult, I only have to see my SH on very rare occasions. (Lyla's bday partys, recitals, etc) He even blows these things off if he has something HE wants to do. Missed her bday party last year, so I didn't see him all year until her recital a few weeks ago.
Your kids are young, so you will have to deal with it for many years to come.