Could this just be paranoia

So my BF and I had children from our previous relationship. My child's father is married but he still tells me time and time he misses me and wants to cuddle and all that. I dismiss him cause of my relationship with me BF and he's married. My BF cheated on me with his baby mama six months ago and he told me cause I figured it out. I'm still not over it. I don't trust them two but he tells me nothing is happening. Sunday morning he rushes me out his house and tells me she and his son our going out. I contacted him last night cause my wallet was missing and it was about 10pm I'm thinking that he's home alone since his son is 5 and should be in bed by now. I was on my way there to find my wallet when he texts me"it's not here and idk why your coming. I'm spending time with my son and his mom" I don't know if I should leave him cause he's still playing games or am I paranoid