Are these all OK?

in the present
He may be in love with you? or He might be in love with you?

in the past
He might have been in love with you?
He might have fallen in love with you?

Question

Are these all OK?

in the present
He may be in love with you? or He might be in love with you?

in the past
He might have been in love with you?
He might have fallen in love with you?

Answer

Generally speaking, yes -- these are correct.

"He might have fallen in love with you" is in the present perfect tense, and can have an implication on current events, even though it began in the past.

Answer

Yes