And, you go and give some poor advice yourself. It's CAPITAL GAINS that losses can be applied to. Doesn't matter how the gains were made, stock, options, futures, etc.
The only other minor US tax issue is "gift taxes" because the IRS will see that you gave your dad X dollars and he gave you back Y dollars. As long as X and Y are less that $13k per year, there's no issues at all and you can do it year after year. If the amounts are above $13k per year, then you need to report the excess gift against a lifetime limit of $1 million in excess gifts (see IRS Form 709). Going over the $1 million limit and actually paying gift tax is a high-class problem, but it's something to consider during estate planning (both yours and your father's).