Grandparents

Hi everyone! My lo is six weeks. He'll be 11 weeks when I go back to work. I'm only going part time so I just need care for him Monday and Tuesday each week. I haven't found affordable care that I feel comfortable with. I am considering asking my dad and step mom. They are retired, live five minutes away and are obsessed with him. He loves my step mom because shes so sweet and gentle with him. Part of me thinks they'll jump at the chance and part of me thinks they'll say no because they want to have that free time. Is there anyone who has dealt with a similar issue and has advice? I don't want to put them in an awkward position.