I have been separated from my children’s dad for a year and half now. He’s got a partner and kids have met etc. I’m with someone but kids don’t know. I’ve known him for years, my daughter has met him couple of occasions over the years as work colleague by coming into my work, but taking it slow with the kids now we are together . We met at a kids activity place so everyone could meet informally ( his child, my one child and she had a friend with her) again, they just thought we bumped into them. Kids played lovely. My question is, should I tell my ex about this? He knows I’m ‘seeing’ him. But not sure how to approach the kids part if kids don’t actually know we’re together.