parameters

txt2img: 

anthro, furry, duo, 2boys, 2males, age difference, size difference, bed, bedroom, precum, sex, anal sex, penetration, licking head, BREAK,
anthro, (young), teen, weasel, brown eyes, naked, sheath, penis, balls, anus, BREAK,
anthro, wolf, grey fur, blue eyes, naked, sheath, canine penis, balls, BREAK,
masterpiece, best quality, amazing quality, very aesthetic, high resolution, absurdres, depth of field, newest, scenery, ultra-detailed, detailed eyes, detailed fluffy fur, dynamic lighting, 8k, HDR, ultra-HD, highly detailed, HDR, realism, realistic, realistic lighting, caustic shadows,
Negative prompt: lamp, (worst quality, bad quality:1.2), lowres, low quality, bad male anatomy, bad female anatomy, grainy, noisy, render, filmgrain, text, deformed, disfigured, (female), (breasts), abs, extra fingers, bad anatomy, signature, patreon, web address, text, feral, blurry, faded, antique, muted colors, greyscale, boring colors, flat, bad photo, terrible 3D render, glitch, cross-eyed, lazy eye, ugly, distorted, glitched, lifeless, bad proportions, watermark, window, human penis, vagina,
Steps: 40, Sampler: Euler a, Schedule type: Karras, CFG scale: 5, Seed: 767109400, Size: 1024x1024, Model hash: 4b7db59db3, Model: novaFurryXL_ilV120, freeu_enabled: True, freeu_b1: 1.01, freeu_b2: 1.02, freeu_s1: 0.99, freeu_s2: 0.95, freeu_start: 0, freeu_end: 1, Version: f2.0.1v1.10.1-previous-669-gdfdcbab6

Some edits, coloring, and then img2img: 

parameters

anthro, furry, duo, 2boys, 2males, age difference, size difference, bed, bedroom, precum, sex, anal sex, penetration, licking head, BREAK,
anthro, (young), teen, weasel, brown eyes, naked, sheath, penis, balls, anus, BREAK,
anthro, wolf, grey fur, blue eyes, naked, sheath, canine penis, balls, BREAK,
masterpiece, best quality, amazing quality, very aesthetic, high resolution, absurdres, depth of field, newest, scenery, ultra-detailed, detailed eyes, detailed fluffy fur, dynamic lighting, 8k, HDR, ultra-HD, highly detailed, HDR, realism, realistic, realistic lighting, caustic shadows,
Negative prompt: lamp, (worst quality, bad quality:1.2), lowres, low quality, bad male anatomy, bad female anatomy, grainy, noisy, render, filmgrain, text, deformed, disfigured, (female), (breasts), abs, extra fingers, bad anatomy, signature, patreon, web address, text, feral, blurry, faded, antique, muted colors, greyscale, boring colors, flat, bad photo, terrible 3D render, glitch, cross-eyed, lazy eye, ugly, distorted, glitched, lifeless, bad proportions, watermark, window, human penis, vagina,
Steps: 40, Sampler: DPM++ 3M SDE, Schedule type: Karras, CFG scale: 5, Seed: 767109400, Size: 2000x2000, Model hash: 4b7db59db3, Model: novaFurryXL_ilV120, Denoising strength: 0.45, Version: f2.0.1v1.10.1-previous-669-gdfdcbab6

A bunch of inpainting, coloring, etc. Followed by upscaling: 

Postprocess upscale by: 1.45, Postprocess upscaler: 8xNMKDSuperscale_150000G