Their blatant flirting had made Sirius intimidating—and a bit uncomfortable to be around—when Remus first met them. It was difficult to know how to take them at times. Now that he’s spent more time with them, Remus was learning that Sirius really is just a huge idiot that doesn’t know how to  not  come on to people. It doesn’t matter who it is either. Remus has witnessed Sirius accidentally make a move on their own brother by not letting a set-up slip by them. While Remus felt incredibly awkward about the whole thing, Sirius had only cringed slightly and Regulus had rolled his eyes before they both moved right from it. 