KILLJOY Oxford University chiefs have told students they can have an overnight guest only twice a month — to cut down on noisy romps.

Some colleges demand a month’s notice from students who want guests to stay at their on-site accommodation — while others must be given permission in writing.

They are also limited to one guest a night following group sex sessions at a notorious party.

And undergrads at all 44 of Oxford’s colleges can be fined or even booted out of their rooms if they break the rules.

Colleges say the measures were introduced to cut down on noise and help students focus.

But one student said: “This shows just how hopelessly out of touch the colleges are.

“It’s like they were written in the 17th Century, when sex was illegal outside of marriage.”

Hertford College students breach their tenancy if they do not have “written permission”. One undergrad there was reported by a cleaner and sent home after having a lover stay.

Students at St Hugh’s College must “seek advance permission from the Dean” for sleepovers.

Brasenose limits members to nine overnight stays a term.

Magdalen College forbids all overnight guests, without exception. Instead students must book a “fellow’s guest room” a month ahead and pay £92.45 for a bed. St John’s College demands notice of sleepovers by email — and denies frequent visitors.

The rules have been revealed after one of the “wildest” years in Oxford’s history — with topless parties, drug-fuelled orgies and “virgin spanking”.

One student said: “If they want us to act maturely, they could start by giving us responsibility instead of treating us like kids.

“Perhaps that’s why Oxford students go so mad at parties, as they’re forced to repress it.”

A university spokesman said: “Colleges need to know how many are on the premises. This is a basic safety requirement in case of fire or other emergency.

“Every individual college has this responsibility and each has a policy to ensure they meet it.”