Awkward situation!! PLEASE HELP!

Long story short: I had this friend of 4+ years. We liked each other at different times but were never single at the same time and eventually we got so close we wouldn’t risk it for a relationship. I started dating someone and things were getting serious so I distanced myself from the friendship which didn’t go well between us and now we haven’t talked in over a year

Now- his parents have me on Facebook and have asked me to pet sit for them while they go on a secret vacation so there runs the risk that he might come home while I’m in his house while his family is gone and he doesnt know.

On top of this his dad has asked me to illustrate his graphic novel (he has two other published books so it isn’t a small project) and now they want me to be their pet sitter for future vacays. I sat at his house for over an hour talking with his mom and dad the other day while seeing the dogs for the first time in 2 years and learning their medicine routine and he doesnt know. (They’re both 8+ years old)

I guess I just need advice on how I should feel about this situation. I don’t want him to feel uncomfortable and his mom said he’s always mentioned asking me to pet sit- but I don’t feel comfortable messaging him about any of this since he has me blocked on twitter and we’re only friends on Facebook now. Plus his parents don’t want him to know about their vacation (he would be mad because of covid but they assured me they’re going to a very private area).