A feminine man or a metro-sexual man. For example a man that waxes his eyebrows, and has manicured nails (possibly with nail polish). It can also refer to a masculine female. This does not refer to one's sexual preference.
stud is a fertile or attractive male and refers to a man, while muffin is a reference to a woman's pubic region and modifies the term 'stud' into a female noun.
Look at those two lesbos. the one's a plush carpet and the other's a stud muffin.