Paint me nude, soft strokes for a soft cuck [bi]

Not exactly cucking but possibly in that broader territory. We’ll call it a soft cuck. Basically I’d like a cute artist friend/acquaintance to first use me as a model for painting while semi-clothed, like in my underwear or lingerie, but then somehow encourages and emboldens me to get completely nude for another painting in the same session. I am a bit nervous but their professional talk to explain and encourage me helps. I want to feel good, confident and sexy about my body, so I do it, and maybe it turns me on too. Cute artist friend with her cute smile praises my body (professionally), makes me blush and turned on even more while naked.

My girlfriend or boyfriend would know about the semi-clothed painting but not the nude one, come into the studio to see how it’s going, get shocked, come up to me to basically say they don’t like it that another person is seeing me completely naked. I tell them somewhat embarrassingly, but determinedly (while a little turned on of course), that I want to do it. They leave, a bit annoyed, but come back later near the end, while I’m in the middle of being really embarrassed that I’m visibly a little wet and trying to make it less visible for art, and the cute artist friend assuredly and professionally tells me “oh it’s completely normal, happens to many people” Which doesn’t help of course, because it turns me on even more lol.