Help! I found my dad dancing with another women who wasn't my mom.

My mom and I found my dad dancing at the Night Club with another lady. *Before this happened they were out celebrating their anniversary together. *
( He went there by himself, after going out with my mom to celebrate their 22nd anniversary. They had an argument, and my father decided to go out dancing instead of fixing whatever issue they both had going on. ) 
Now the thing is, what advice would you guys give me and my mom to move past this. What are your thoughts on this ... ? Thanks.