plugin option has gone in the admin panel
 

now im not the admin that installed vbulletin. im the admin that uses it with him. he trusts me wiv evrything on the site. and i went on today and i go to admin panel. and the plugin system has gone. lol wierd. like i cant select it from the list on the left because its vanished. reminds me of the time i was cooking and i went out to get something den i came back and the food had gone from the bowl. but later on i found out it was my cat.

That person has obviously edited your administrator permissions and disallowed you access to it. You will need to speak to him (there is a way you can reinstate it yourself, but its best to speak to him)