I am 16 year old and one boy in my class has a habit of masturbating and he did so on the last Friday, and according to him whenever he does so, the semen stays on his pants. That day he had some cash in his pant pocket, he gave it to me and I saw that some liquid was there on the note which was concentrated on two different spots. I was sure that it was not sweat, but he convinced me that it was sweat and I ignored the thing and roamed for nearly 20 minutes, by that time the liquid was no more on my hand and then I started eating with the same hand. Now I'm not sure if his sperm cells are in my body and even if they are there what shall I do, will they flow with mine or my blood or just get excreted, or some manipulations in my health or body?