Optional second argument to /tpaccept, it will only accept the request if the sender matched that string.

Essentials/src/com/earth2me/essentials/commands/Commandtpaccept.java

@@ -26,6 +26,11 @@ public class Commandtpaccept extends EssentialsCommand
 		{
 			throw new Exception(_("noPendingRequest"));
 		}
+		
+		if (args.length > 0 && !target.getName().contains(args[0]))
+		{
+			throw new Exception(_("noPendingRequest"));
+		}
 
 		long timeout = ess.getSettings().getTpaAcceptCancellation();
 		if (timeout != 0 && (System.currentTimeMillis() - user.getTeleportRequestTime()) / 1000 > timeout)

Essentials/src/plugin.yml

@@ -348,7 +348,7 @@ commands:
     aliases: [etpaall]
   tpaccept:
     description: Accepts a teleport request.
-    usage: /<command>
+    usage: /<command> [otherplayer]
     aliases: [tpyes,etpaccept,etpyes]
   tpahere:
     description: Request that the specified player teleport to you.