I have split up with my husband and met up with one of his best mates it started off as friendly texts from him I then met him and went on from there. This has carried on for 5 months one minute he tells me that I mean the world to him, am the perfect girl for him, he has cooked for me do men go to all this trouble if they are using you.

They can, but usually not.

I went on holiday and we talked and text all the time when I got home he said he really missed me. I thought all this talk was quite heavy from a bloke.

Yes, it is, it takes a bloke a lot of guts to say "I miss you".  Men tend to hate emotional talk.

I really like him and he knows this now he has stopped texting so much just on a fri or sat the days he knows I could be out as I also have children he is now having problems with his son who is not well and has said that it is off for the moment but to keep texting him I don't want to cut him out as I do like him and his son is not well but I do'nt know what to do know should I text him on a friendly basis I just think if he likes me that much he would'nt cut me out altogether !

You are both in a very difficult situation.  You both have children, who should be the priority to both of you.  You both have partners (or ex-partners), you both have failed relationships.  That is not a very easy situation to get a relationship from.  Something somewhere is likely to clash.  Whether it be your children, your ex-partners, or both of you.  Then are too many people involved for it to stand a good chance of working.  You are both probably very cautious because of the effect on your children and the fact that you both have failed relationships.  Some people do make this situation work, but there are a lot more, where it doesn't work.  What you certainly need to do is give it time, give it time to work out whether it will or won't work.  You can't just drop children one day and fly off into the sunset and have a relationship and live happily ever after with someone.  It has got to be a gradual thing and you certainly can't push a bloke into making quick decisions in this situation.

I know his son comes first, is this a nice way of him saying goodbye or should I cut him out altogether which I don't want to do if I stop texting and he is interested will he get in contact with me.

All you need to do, is to remain friendly with him.  Give him some space, don't be over-possessive and don't text him too much.  Be understanding, because you would expect him to be understanding to you if one of your children were ill.  You'll see eventually whether this is going to work out, or whether you should move onto someone else.  In the meantime your a free agent so if someone else comes along, you should make yourself available if you like them.