s 78 “Sexual”
For the purposes of this Part ( except sections 15A , 66B to 66D and 71 ), penetration, touching or any other activity is sexual if a reasonable person would consider that— (a) whatever its circumstances or any person’s purpose in relation to it, it is because of its nature sexual, or (b) because of its nature it may be sexual and because of its circumstances or the purpose of any person in relation to it (or both) it is sexual.