-Punch Meryl prior to fighting Psycho Mantis. She will chase and punch you.
-In the main hall on the floor where you fight Psycho Mantis on, go into a cardboard box and look at Meryl. The longer you look at her, the redder her face gets. She also will make some comments.
-After facing Psycho Mantis, equip your scope and zoom in on Meryl's chest. She will say "What, what is it?", "What are you staring at?", "Snake, don't look at me that way.", and "Come on, we don't have time for this."
-Look at Meryl with the scope or camera to annoy her.
-After going to all floors, go back through the ventilation shafts and back outside to the chopper area. Call Meryl and she will say that you don't know where you are going.
-Shoot Meryl with any weapon during the first battle with Sniper Wolf without leaving to get a sniper. You will get hilarous calls. The more you shoot her, the more funny calls you will get.