I’m currently 4 months pregnant with baby number 3. 2 kids from a previous relationship.
I split with baby no3’s father around a month ago. He is a very lazy, selfish man and where he’s highly intelligent, he very much lacks common sense. We were constantly arguing about him not pulling his weight, lying around watching tv while I did all the household chores, cooking etc. We also argued about him not making an effort with my other 2 kids, to try and establish a good, solid and stable relationship with them, even though he said he loved them as his own and very much wanted to take on the role of stepfather.
Anyway, I though it best we call it a day as being in a relationship with him was causing me more stress than it was worth. We hadn’t really spoke much but he was still keeping in touch with the kids and taking them on the odd day out (bowling/cinema) as I seen he had been making a bit more effort with the kids, I asked him last week if he wanted to talk about the possibility of getting back together, I said we could establish some ground rules of what I expected when he was at mine and with regards to him helping out with the kids etc. He said no as when we’re together it just causes problems. I told him I respected his decision and that as long as the kids still wanted to have a relationship with him, then I would not stand in the way of that.
Here’s my issue.....Both kids got amazing reports from school last week and he offered to take them out for dinner tonight as a treat. He then text me asking if I wanted to go. I said “yes that would be nice” (im totally fed up at the moment without any sort of social life so thought I may as well go and get out for a night) he’s found reasons to text me every day since then (Tuesday this week)
I just feel so confused by it all. Why is he texting me and inviting me for dinner? I’ve also got it into my head that he may be seeing someone else and what if they contact him while I’m out with him 
it’s none of my business if he is but I think it would destroy me knowing I’m carrying his child and he’s moved on so quickly.
I’m now thinking maybe I should make my excuses and not go to dinner with them, let him have a night with just the kids.
Am I being unnecessarily paranoid and thinking irrationally? I swear these pregnancy hormones have a lot to answer for!