Your GF's Tits Have Grown Massive - Cow TF (Patreon)

She signed up for an experimental breast growth supplement derived from bovine growth hormones. She only took one dose. Now she's all furry with a black snout and gigantic tits. She retreats to this old shed on your property when you have company over. She doesn't want to risk being seen or heard - she's recently started to have controllable mooing fits.