My advise would be to go for the job that is a wise choice for your immediate future. The second job sounds to me like the best choice for the situation you are in right now (flexibility, security, and marketable skills). I think you should act as if you are by yourself, and not put life or decisions on hold for the M's sake.
Also, you know that H wanted you to work, so win-win, right?
What do you mean you have no reason to trust L - do you have a reason to distrust your L?
M 16 yrs, WH62, P54 3 adult blended kids EA 11/13, BD1 6/14 PA fall 14, BD2 2/15 Piecing 2015, BD3 12/15 Separated 4/16 WH moved OW in 5/16 Divorced 6/15/17