Do you know you can suggest same persons profile as a friend to him? With this trick one can able to get friend suggestion of his own profile.
What you need :
You need victims profile ID and you must be in his friend list.
Note: If you don't know how to get someones profile ID then
Go to https://graph.facebook.com/username (replace username with victims username) and get facebook profile ID of victim.
Follow following steps :
1. Go to victims profile page. (This person will get a friend suggestion for his own profile which will be suggested by you).
2. Hover over the Friends button and click on Suggest Friends.
3. After click Suggest Friends... you will get below pop up window in front of you.
5. You will now able to see code behind current Facebook webpage. Just find below highlighted field and replace "data-uid" and "value" field with victims Facebook ID which you obtained earlier. (In below figure you can find VICTIMS FBID field in red font. Instead of that use Facebook ID of victim.
6. Click Enter and go back to previous Suggested fried Popup window and click suggest friend now. You might able to see the same person in suggested friend list now.
7. After click on suggest friend button the person will get friend suggestion for his own account.
8. It will show error message when person try to add himself.
Do this trick with your friend and entertain him and yourself.