I once dreamed of kissing the boyfriend of my classmate?...?

Question

what does that means?

Answer 1

To dream that you are kissing someone else's boyfriend or girlfriend, indicates your wish to be in a relationship and to experience the energy of love. You may be sexually acting out and desire to awaken your passion. Alternatively, it indicates a lack of integrity on your part.  

hope this helps =)

Answer 2

Either you are angry at your friend for something and want to get back at her, or actually have feelings for the guy.

Or your brain could just have been sorting out the junk from the memories and threw a memory of him and one of kissing a guy out at the same time.