Found him kissing his Ex wife

What is the question? How to get over this? How to break up?

No contact is a great place to start.

Not enough info.
What KIND of kiss? Where, when?
A kiss isn't always a kiss of passion.

Regardless of any type of Kiss Wrong Wrong id pop a little washing up liquid in his drink so he can rinse that cheating dirty mouth out!! Be strong :):) Hugs