Supergold
What do you think Booster's sister will react when she sees Superman flirting with her brother? Will she try to keep Superman away from Booster? Rip hunter also like get away from my dad oh wait he can't tell that his dad
Michelle very loudly in front of Clark asks Booster "Hey Mike, isn't he the guy you had a giant poster of in our bedroom and wrote 5 college essays about" because it's her job as his sister to embarrass him as much as possible
I don't think she'd be too protective of him, he's an adult and by their own admittance they weren't close as kids so probably never developed the "shovel talk my sibling's partner" protectiveness
As for Rip...it depends how he's related to Clark in this scenario. If Clark is just some old bf of his dad's he's probably pretty indifferent and just gets mad when Booster tries to bring him onto the Time Sphere or Vanishing Point because he's a liability
(Or if he's a past bf that Rip had no idea about, that's when he might be a little hostile because from what he knows, Superman has a long history of discrediting his dad publicly)
If Clark is his other dad and/or was around for his childhood, it's mostly the same as he treats Booster. Gives him a hard time but it is all in the name of love and hope that he'll become the person he remembers him being. From the outside it probably looks like the same indifference as scenario one (he has his secrets to keep after all) but he might give more leeway on Clark joining them for missions
