There you go again, with your shallow understanding of the issues. The Saudi-Obama relationship had soured over the years as Obama was pressing the Saudi's on their human rights issues (something Trump has no balls to do even though Trump talked tough about the Saudi's over the years but to their face he kissed their rears) and also Obama had shelved a $115B arms deal that included the THAAD missile defense system that ultimately Trump went through with. Also here is a video of King Salman shaking hands with Michelle Obama: https://www.youtube.com/watch?v=5UQMs-Hr7dA
You really should educate yourself about an issue before you comment on it...