What do I need to do to get my child support increased?

My kids’ father has gotten remarried to a woman who earns a lot of money. He has barely paid me any child support in the 3 years we’ve been separated. Now he drives a nice car and they go on vacations with my kids and eat out every night. Can my child support be raised based on this new money he’s acquired? My kids are starting to want to go to his house all the time and not stay with me because he has everything at his big house for them – video games, motorbikes, etc. It’s not fair that I’m struggling.