sometimes when guys work all day they need that unwind time/decompression from a busy/stressful day. Do remember that guys are not chatty like women are. Sometimes guys do better with kids when they ask him a direct question or when it comes to physical activities.
Yes, you may be upset about something, but it's very difficult for guys when we run off and to call a friend. it's like advertising to the world that they did something wrong. If he's not quick to temper, then that should be a cue that something else may be bothering him. As we women are emotionally triggered creatures it's easy for us to get upset and snowball, but if we can step back and say somthing like "I know you've had a rough day, I can listen if you like." then walk away and let them have time to decide their plan. Easier said than done sometimes.
Try creating some activities, like him taking the kids to the movies, or as simple as interacting with them on chores. Blended families are not easy, and the kids need to understand too that it's baby steps. Take one day at a time.
something a friend did was create a journal, and each night each person had to go around and say 5 things they were thankful for and 3 things that irritated them today. It's sometimes very easy to think of negative things, but harder to do positive. It's interesting because when you go back and look at what you done after a while it can give you a bit more perspective.