<human>: Can you give me the gist of the text in a nutshell?

In light of recent events, I have discovered that my 37 year old mom's live-in boyfriend (31) of three months is a cheater. Before her, he's been in and out of relationships every other month. Now he's talking about rings and getting a house with my mom after almost three months of dating and a month of living together. 

My best friend (24/f) has been receiving sexual messages and pictures from him after adding her on Facebook. She's pretty uncomfortable by this, but it has since escalated. He is now buying her gifts and giving her money in hopes of sexual favors, but she hasn't acted on this. Instead, she has accepted the gifts and told me what has been going on. Now, this friend loves my mother and Mom loves her. But this is ridiculous. 

My mom has actually gotten suspicious of her bf because of his texting habits and secrecy... and he reveals too much to my friend. He has cheated on my mother a few weeks ago, claiming it wasn't worth it, yet offers to get a hotel room for him and my friend. And to think she and I both liked him and thought he was a good guy for my mom. 

The bf works offshore and is only home every other week. My friend and I usually visit my mom a lot, but this has made it incredibly awkward for us. I don't want to see my mom hurt. My friend told me this in confidence and she trusted me to take this to my grave.

This, though, isn't eating at me like I thought it would and I know I won't spill the beans unintentionally, but I'm just not sure what to do. It's definitely a crazy situation to be in and it's incredibly delicate. I could let this run its course, however, and hope my mom comes to her senses and looks into her suspicions.
<bot>: mom's bf is a cheater, both physically (with another woman) and emotionally (with my best friend and possibly others).