If both the female and male were wearing underwear, i.e. panties and boxers, and they rub their genitales together (dry hump), but he does not ejaculate, can the girl still get pregnant? Could the female get pregnant if he had a wet spot from pre-ejaculation on his boxers?

A woman can’t get pregnant this way. Pregnancy is possible whenever sperm get in a woman’s vagina. This may happen during vaginal intercourse, but it may happen during other kinds of sexual activity, as well — but not if the man does not ejaculate.