i don't believe that is a sin, its what it LEADS to that would be considered a sin. Paul says in 1 cor. 7:1 that it is better for a man not to touch a woman. (kjv) this would help prevent other emotions getting in the way
In such a case, the Hindu suggestion would be to get married. Sex within marriage is perfectly OK and necessary part of life (not just for procreation of children but for enjoyment also).