Can you get pregnant if a boy is wearing underwear and your not?

No, you cannot get pregnant if a boy is wearing underwear and you are not. Pregnancy can only occur when a sperm cell from a male fertilizes an egg cell from a female. If a boy is wearing underwear, it does not mean that his sperm cells are getting into your vagina. In order for fertilization to occur, the sperm cells must be deposited inside the vagina. This can only happen if the male ejaculates (when he comes) inside the female's vagina.