Is there such a thing as seasonal bisexuality?

My husband and I had a dear friend of ours over for dinner tonight. She "came out to us and wanted to have someone to confide in. She's in an ongoing 10yr marriage with her husband. She still is blissfully in love with him, but claims she is season bisexual because only during 1 time of the year, she has the preference for a female companion-- she stressed not in another other manner than sexual-- that she doesn't want anything more than a 1 time incident a year. Is that not considered bisexuality?? I really want to be supportive, but I think she is getting confused with the terminology of ones sexuality.