what is he doing here

so my ex of 3 years... who im still pregnant to with our 3rd child is back with his ex since a month after we broke up. they also have 3 kids. his ex dosent like my kids... but last night at 2am.... 5:15am and 7:36am he was texting me... trying all night obv to get my attention... but i didnt bite or respond. so today he came and picked my two kids up.... and 15mins later he drove past me with her also in the car.and there kids.... wtf so shes now stepped in and is playing step mum to my kids. i again didnt text or anything which i normally would. im trying not to let it bother me. but it is.... im so down and hurt and dont feel ready for this. how is she even ready to be around my kids.... he had got me pregnant with our first while he was with her. and our second and there 3rd is the same age. yes i know i dont need bashed for all that mess. i just feel so hurt and down. but i dont want him to know that. obv they where fighting last night if he was looking to call to mine ans texting me. yet has her with my kids today...