How do you forget about their children?

Crazzzzy weekend, but stbxH is finally out of my mom's house after a 3 hour stand with my 2 aunts basically forcing him to get out because he refused to (and legally he has to be 'evicted' since he lived there more than 30 days, but who in their right mind would want to stay where your not wanted?!?) but anyway, I got a do-it-yourself divorce kit from a paralegal and i'll be filling out the paperwork soon.

anyway, how can I just forget about sd? I already miss her. She's such a good kid and she was asking stbxH about me, when he told her he was moving back to his hometown (which he really doesnt want to, but sd and ALL his family there so he has no choice almost unless he wants to fail here) and she asked if me and her were still friends and if she was still going to see me and grandma (my mom) I dont know if he was just telling me that to make me feel guilty (which I think partly he was) or what. He keeps trying to text me crap and its getting annoying. I was only talking to him so we could decide what all he was going to take with him and he had to bring her up! hopefully soon he'll be able to sign the paperwork and we can get on with our lives. Next time I wanna make sure I dont get with a man with children, because at this point, its harder for me to break up with their children then it is to break up with him!