Would "Il ne prend pas le soleil" work?
(This is the first time I've ever seen "sunbathe," and the dropdown menu was completely empty, so I asked Google Translate to give me a quick English translation....)
prendre le soleil implies that he is a plant ^^. In French, there is no actual verb for sunbathe. We use bronzer for people (which means to get tanned) or prendre le soleil for plants or objects that actually need sun to function.
WordReference lists both definitions, and discussions about what word to use seem to treat them interchangeably, so I'd say go for it.
That to me would translate to he doesn't tan. Sun bathing means basking in the sun, translation should be acceptable
I am confused: Does "bronzer" mean to lie in the sun, or to actually turn brown? They are two very different things.