What is the right verb to describe someone's extreme liking of something trivial?

For example, someone really likes pictures of vegetables (not even sexualized pictures) and he's a super nerd of vegetable pictures, how do you describe his behavior when he starts babbling about those boring and trivial pictures?

In other words, what is the right word for this sentence "Bob ___ over his vegetable pictures again"?

Is there another word other than "nerd-out"?

I suggest that a one-word answer is going to be hard to find; two or more words might work, however. Here are a few possibilities:

"Bob is fixating on his vegetable pictures again?"

"Bob is fixating childishly over his vegetable pictures again?"

"Bob is obsessing puerilely over his vegetable pictures again?"

"Bob is infantilizing over his vegetable pictures again?"

With an ironic tone, an observer of Bob could say,

"Bob is waxing rhapsodically ad infinitum and ad nauseum over his vegetable pictures again?"

"Bob is lost in reverie over his vegetable pictures again?"

How about a simple insult?

"Bob is inanely poring over his vegetable pictures again?"

"Bob is admiring insipidly his vegetable pictures again?"

"Bob's insipidity knows no bounds when looking at his vegetable pictures."

"Bob is looking prosaically at his vegetable pictures again?"

"Bob is indulging his plebeian taste for vegetable pictures again?"

There's the verb geek^1.1 (or geek out):

Be or become extremely excited or enthusiastic about a subject, typically one of specialist or minority interest:
I am totally geeking out over this upcoming film.

So your sentence becomes: