My Little Sister Was Made to Pee on Me Repeatedly After I Let Her Use the Bathroom First… Incest, Urination, Piss Drinking

My sister-in-law came to visit my house. After dinner, I let her use the toilet first, but she couldn't hold it and ended up peeing right there. Then, something snapped in her—she started peeing on me while I was still cleaning up. From that moment on, an intense, forbidden relationship began where she dominated me with her urine. Was she secretly aroused by my M-side all along?