I noticed that my husband spend more time with his other child than our own child lately, so I plan to confront him one of these days . How would i do it ? Is it advisable to confront him and demand more time with us ?

Did you have an agreement prior to having your own child? If so, you can go back and remind him about what you have agreed upon when it comes to spending time with his kids. You should come up with an agreement moving forward so you won't have any conflict on how he divides his time with the kids.