This is all worst-case addict behaviour and I hope you will keep yourself and your children safe from this man...as in no contact at all.
When he went for the bike, you can believe there was more involved...he may have let them hold the bike for dope and then not paid the money owing...or something as dangerous...and there could have been violence or the police could have become involved...and you and your children would have been right in the middle of it all. You could have been charged because you were driving and your girls could have been taken away from you. I don't mean to alarm or upset you, but it is THIS serious.
Your jewelery has probably been pawned for dope money too, this is textbook active addict behaviour and you don't need to prove it to know it.
Sweetie, I know you are trying to make some kind of good relationship between this man and your daughters, but it is simply not possible while he is in active addiction. His word means nothing, saying he's clean never makes it so.
Please put on the brakes and keep your daughters and yourself a safe distance from him and his addict behaviours. It will only get worse and I fear for all of you.
Hugs