There’s a contradiction of terms in your final statement that I think points directly to the answer you’re looking for.
Erotic and sexual I think so go together, especially when you start to factor in more people than just yourself. While you can control your own feelings in a situation, most people, once aroused, are not so keen to “walk away empty-handed” (so to speak).
The contradiction comes when you introduce the phrase “sensual touch”. To me this is something that is shared and enjoyed for its own sake, without needing to turn into something more. If the act is being used in order to create arousal, I don’t see it as being sensual anymore - at that point it has crossed over to erotic/sexual.