We thought we knew what Aaron Patzer did last summer, but we didn't know the half of it. Sure, Patzer sold his Mint.com for $170 million. But he also had a sexy tryst with a London artist. And her sketchpad.

Now, we can understand why the founder and CEO of personal finance startup would be into the concept of transparency. After all, Mint.com is the sort of site that only works if you hand over online access to your bank accounts, credit cards and investment holdings. But, for all the naked ambition and passion for openness in the Valley, we never thought anyone, even the likes of Patzer, would go this far.

So we've been trying to figure out how the entrepreneurial computer engineer came to allow nude charcoal sketches of himself to appear on Rebecca Commissaris's website. Based on information from a tipster with knowledge of the pair, a review of the website in question and a gander at Commissaris's Facebook fan page, this is our working theory:

Patzer and Commissaris hooked up in London last summer. One thing led to another, Patzer ended up in his lady friend's bed, and, enraptured with the artistic possibilities of his physique, Commissaris busted out her canvas.

This would explain why the first sketch of Patzer appeared on Commissaris' site in August, with the caption "Aaron relaxing on his arm in bed" and the title, "Relax - Male Nude in Charcoal." The same day brought "Embrace," featuring the naked back of a woman who looks like Commissaris and who is nuzzling up to an apparently nude man who looks like Patzer

Then, a romantic hint of fleeting long-distance love: the September work provocatively titled "Before Disappearing." The subject, clearly Patzer, is seated naked on a bed, and allows us to examine the best-protected holding in his portfolio, hedged only by a carefully-leveraged tranche he's folded off from his core asset pool.

We're not ones to underestimate an attractive, young, foreign artist's effect on even the most coldly logical of the Valley's startup geeks. But Patzer has been especially careless, not only allowing his (first) name to be used in one of his lady friend's captions but also going so far as to plaster his (full) name all over her Facebook fan page, where "Aaron Patzer likes this" is attached to several of Commissaris' sketches — including his own "Before Disappearing" nude. (Sadly for his ego, no one else "likes this" sketch yet, even though 10 Facebook users gave thumbs up to the art posting above and three to the one below.)

Between these sketches and Oracle co-president Charles Phillips's very public dalliance and breakup with billboard-renting girlfriend YaVaughnie Wilkins, we're starting to wonder if fameballing-via-indiscreet-romance is becoming a new pastime for wealthy Valley executives.

Patzer, at least, is unmarried, unlike Phillips. Which brings us to the most heartening theory about the drawings: Maybe he's just a fool in love. Our tipster did call Commissaris his "girlfriend." Judging from her work, she sees something, uh, special in him too. In that case, mazel tov.

Below: Screenshots of the sketches as shown to the public on Commissaris' website, one of Patzer's Facebook notes, and two pictures of him with clothes on, for comparison. Click to enlarge. If necessary. Ahem.

Naked Emotion: Mint.com CEO Bares Assets for Lover's Art

Naked Emotion: Mint.com CEO Bares Assets for Lover's Art

Naked Emotion: Mint.com CEO Bares Assets for Lover's Art

Naked Emotion: Mint.com CEO Bares Assets for Lover's Art

Naked Emotion: Mint.com CEO Bares Assets for Lover's Art

Naked Emotion: Mint.com CEO Bares Assets for Lover's Art

Patzer on his Facebook profile.

Naked Emotion: Mint.com CEO Bares Assets for Lover's Art

As photographed by pilosophygeek on Flickr

Naked Emotion: Mint.com CEO Bares Assets for Lover's Art

Patzer at a TechCrunch event.