[PAULUS libro sexto ad Plautium. ] §23.2.39.prSororis proneptem non possum ducere uxorem, quoniam parentis loco ei sum.
[PAULUS, in the sixth book on Plautius.] I cannot marry my sister's great-granddaughter, because I am in the position of a parent to her.
§23.2.39.1Si quis ex his, quas moribus prohibemur uxores ducere, duxerit, incestum dicitur committere.
If anyone marries any of those women whom we are prohibited by custom from marrying, he is said to commit incest.