Puzzled by Petrics

Six JSC students, Jane, John, Erin, Frank, Ester and Jose, come to a river crossing while on an Outdoor Education trip. They have only one boat amongst themselves which can only carry 2 people at at time. There is however an additional complication which is that Jane and Frank are dating, as are Erin and John, and so too are Ester and Jose. To avoid scandal, it is decided that no boyfriend or girlfriend should be left on a shore with a member of the opposite sex unless their significant other is present. Can the party get across the river with this condition? If they can, how few river crossings are required? Stop by and say “hi” to Professor Petrics in 334 Bentley Hall, and check your solution!