The only occasion a mature escort runs into legal problems in London is if she shares a apartment or condo with one more girl so that these individuals can make one another safer. Then these people are carrying on a brothel and may possibly be detained. Which is just not right.
As for “plain sexual activity” there is no limit to the means in and that a woman can outline her ministrations, the postures and varieties she will make available, her asking prices and settings and everything else she might choose. As long as it is presented in an adult-only channel. She can reveal photos of herself partially nude, naked, in corsets or swimsuit or entirely dressed. Just about anything she thinks will attract the right kind of patron. A woman can also reveal images or video clips of herself acting out sex-related acts on her own or with other people. Provided that everybody in them has offered their agreement and there is no subject matter that could go against any other laws.
A contemporary British television programme demonstrated that in excess of 90% of British women and men in their 20s still presumed that it was illegal to be a London escort. These people did not understand that any girl can peddle sex anytime she wishes provided she pays for her taxes and does not violate other legislation along the way.
So a woman can showcase that she is content to carry out oral sex without needing a contraceptive (Oral Without or OWO), that she is contented for a male patron to unload into her mouth (Cum In Mouth or CIM). A male can surf specifically for a female who is more than happy to do butt sex (A levels) or possibly go down on him and lap against his arse and handle analingus (Rimming, or tossing the salad. I have no idea why the last expression applies. My creativeness stops working completely at that point!).
In contrast to the common view, offering sexual activity in England is fully legal. Shopping for sexual activity is London is completely legal. Obviously, both parties must be of legal age, engaging voluntarily, and can not have been subject to any variety of human trafficking. And soliciting in the road is banned, as is advertising in telephone boxes. That very last could seem to be unusual to any person who does not recall the difficulty of opening up the door to London phone booths in the 80s because they were so chock full of postcards that the entrance barely worked!
But that aside, a young lady is utterly at liberty to sell her erotic services as a London escort. And a gentleman is totally permitted to engage the services of high class escorts (or an astonishingly poor level London slattern!) at any time these individuals wish, to do just about anything that these people choose. Girls can publicize on the internet and be as obvious as these people decide on, given that the selling and acquisition of intimate ministrations is totally within the legislation. But lots of people do not realise it.