Is sexual orientation versatile?

1) Mr. L has got 8 GFs before... After he broke off with his 8th GF, he got attached to a guy and thereafter he had 5 BFs. Mr. L is single now.

2) Ms. D always has the hots for cute guys. Recently, she was attached to a lady, who was after her for many years. They are in a blissful r/s now.

3) Mr. J told me he is bisexual. But he is turning gay soon. Mr. J is single.

4) Ms. A had no interest in guys. She would jump whenever a guy touched her. She is happily married now.