This is an important factual topic that hasn't been discussed. As someone who lost his father to assasins, I can tell you that I would love the opportunity to have a smoothie with my dad. But he's at the bottom of the North Sea as far as I know.
It isn't hard. Pick up the phone and call your dad (or a relevant "father figure" who has been kind and informative during your formative years of information collection - done primarily in the youth in homo sapiens and primarily ending once the individual begins regularly tuning into Fox News which is much better to do the thinking for you than your brain. I recommend it) and say something like, "Would you like to go out for a smoothie with me?"
You will find that miracles do happen. They will happen to you if you go out for a smoothie with your dad. I promise.
"Dad? Hi! Would you like to join me for a smoothie? No other drinks or food will be available. Smoothie only. That's the deal." Going with this will help you define the scope of the smoothie encounter. State the rules up front and then you don't have to be rude and cut dad off when he tries to order something else. He knows the rules up front.
If your dad or relevant father figure is "dead" or a right bastard, call a friend and go out for a cocktail. There is safety in numbers.
God bless.