Offensive swear words should also be deleted in lessons and productions for children under 16.
The draft advice for the teaching of drama, developed by all four qualifications, curriculum and assessment authorities in the UK, aims to protect children from possible physical and sexual abuse.
It was a key recommendation of the 2004 Clywch inquiry into allegations of child abuse at a Welsh-medium secondary school in south Wales, Ysgol Gyfun Rhydfelen, in Pontypridd.
In his report, Peter Clarke, children's commissioner for Wales, claimed former teacher John Owen used drama as a "vehicle for improper activity with children" in the 1980s and 1990s.
Owen, known as "Johnny Lickers" by his former pupils, admitted getting two 13-year-old boys to dance naked during a rehearsal. Witnesses described the dance scene as "simulated buggery".
A sixth-form girl also described hearing another student refuse Owen's direction that she masturbate a male classmate. Owen, who resigned from Rhydfelen in 1991 after complaints from a parent and allegations of abuse from pupils, went on to write and direct a long-running children's series for Welsh-medium TV channel S4C, based on a fictional school.
He committed suicide in 2001, after being charged with one count of buggery, two of attempted buggery, and two of indecent assaults against children.
The draft guidance sets out new boundaries, telling teachers how they should deal with love scenes of a sexual nature, offensive language, touching pupils during lessons, and the taking of photographs or video clips.
Teachers are advised to use a "commonsense approach" when judging how far to act out love scenes. But nudity and deliberate sexual contact are considered no-go areas for those under 18.
Kissing is a grey area, where teachers need to ensure the "integrity and coherence" of the performance without embarrassing pupils or staff.
Teachers are advised to improvise, and replace explicit actions or gestures in texts, and ensure that children are comfortable with what they are asked to do.
Managers should agree appropriate texts with teachers, be aware of rehearsal times, and make unannounced visits to classes.
Catrin Davies, head of drama at Tregaron secondary school in Ceredigion, said: "I leave the love scenes and romance out of Romeo and Juliet but wouldn't avoid doing the play altogether. It might sound hard to do with the story line, but it is possible to convey emotion in other ways."
Amanda Sweet, drama teacher at St Cyres School in Penarth, said: "As a mother I would decide what I would feel comfortable for my children to do in lessons."
Consultations on the draft guidance close on April 7. See www.learning.wales.gov.uk