What do you guys think?

My mom started dating this guy and quickly after a few months the guy moved into my mom apartment. Then quickly after he moved in he marry my mom. They’ve been together for 5 years now and there’s a lot of sketchy things. One day this random lady rang our doorbell asking for him, no one knows this but my stepdad. After we told him someone was at the door for him he quickly ran out and left with the lady then he came back telling my mom that he owe the lady money but we’re confuse on why she even have our address…. He then took my mom to change her phone number because he stated this lady is evil. The lady had called my mom btw but my mom didn’t end up picking up…. Another weird thing that happen was on one time my mom was looking through his phone and she saw text messages saying that once he bring his kids into the country he’s gonna leave my mom. Another thing that happen was on their joint account my mom found 3 to 4 transactions of him using the joint account to pay for an Inn close to his job. He claimed that his friend always ask him to pay for stuff for him etc and the friend would pay him back so the Inn was purchased for his friend… we couldn’t ask his friend though cuz his friend would probably lie but it’s so sketchy. Also this man moved his 3 kids into my mom 2 bedroom apartment. My mom already got two kids, my sister and I. So now we don’t really have any space in the apartment. Also the most important information is that my mom pay the rent on her own with no help from this guy. I was told he help once in a while with rent but she’s currently paying for the rent, groceries etc for everyone. My mom seem to be really happy with this guy though and she seem to really like his kids but sometimes my heart break for her. She deserve better. Let me know what you guys think.