my ex who lives with his girlfriend has recently had a new baby boy. our son lives with me who is nearly 4 is now showing a change in his behaviour. his dad frequently cancels visits and i have never had a new man in my life. can anyone help me on how to deal with my sons behaviour, he is becoming agressive, and at school he is hitting other kids and drawing on their work. at home he is loving until he gets angry and will throw his toys. i spend lots of time with him and lots of love, and hugs.
im not sure what else to do. i have spoken to his father who blamed me!
thanks

I hope things have got better for you since this post.
I am in a simular situation, i have been seperated from my sons dad 7 yrs the boys dont know there dad he visited 2 yrs ago, it was a yealry visit but who knows when the next one will be. at times the boys show signs of needing a mans in fluence but most of the time are settled. your child will grow out of this and do not blame yourself you sound like you have done a fantastic job with him. what have the school said about his behaviousr?

It must be obvious to everyone (except your ex) that your boy is angry with him - so often the way that the person who causes the anger is absent and others take the flak.
Nothing wrong with having a new man in your life, just remember to take things very slowly at first, and that continuity is the key. You may find that if you 'move on' your ex will take more of an interest in the boy - it's a possessive thing he won't want another man doing daddy duties.