Is he cheating?

My boyfriend has two daughters both by different baby mamas and he is constantly going to see the one sometimes he goes to see her twice a day and it's always everyday he has not missed one. Sometimes he ends up staying the night and he tells me that the baby mama had left without telling him. Sometimes he doesn't get home till 4 or 5 in the morning saying he fell asleep or his daughter was being restless. Sometimes they do things together him his baby mama and his daughter like go to lunch or they did fireworks when me and him were suppose to be going out. He spends more time over at her house than he does at out house with me. The baby mama doesn't know about me because he's scared she will take his daughter away. There's a lot of red flags and I'm lost.