Should i attend my dads wedding?

My dad is getting married but I have mixed feelings about attending the wedding. I feel that he had an affair before leaving my mum and was responsible for alot of hardship. The evidence is stacked against him. However my mums a nut and can understand why he left her, but shes got a really nice side sometimes, I think shes going through menopause or something. Like she will go nuts about the smallest thing and scream and stuff but then she can be really nice other days. My dad objected to trying and working it out as i suspect it was because he had eyes for the bride to be and i resent him for that but i still care for him. i dont want to confront him or anything because i never land home on my point and the conversation never goes the way i think its going to go. SOO my question is.. should i attend the wedding?